The Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule III for Model Years 2022 to 2031 Passenger Cars and Light Trucks

A passenger automobile is defined, in part, as an automobile “manufactured primarily for transporting not more than 10 individuals.” \1274\ When the agency first issued vehicle classification regulations for the CAFE program in 1977, the agency considered the meaning of “primarily” in addition to the meaning of the phrase “manufactured primarily for transporting not more than 10 individuals” in the context of vehicle classification.\1275\ Ultimately, NHTSA determined that the phrase consisted of two criteria for passenger automobiles: (1) that passenger automobiles must be designed to carry 10 or fewer persons and (2) that passenger automobiles are “chiefly” for carrying persons. In the 1977 final rule, NHTSA noted that, if “primarily” were interpreted to mean “substantially,” almost every automobile would be a passenger automobile, because a substantial function of almost every automobile is to transport passengers. As a result, NHTSA instead interpreted the word “primarily” to mean “chiefly” or “predominantly” \1276\ and established criteria for the classification of an automobile as a non- passenger automobile based on the presence of certain chief characteristics. In the 1977 final rule, NHTSA stated its belief that “passenger automobile” include only those vehicles traditionally regarded as passenger cars (i.e., vehicles whose major design features, including body style, reflect the purpose of carrying persons). NHTSA also provided examples of design features that, singly or in combination, would indicate that an automobile is not a passenger automobile: an open bed for carrying cargo; heavy-duty suspension; and greater cargo-carrying than passenger-carrying volume.\1277\

\1274\ 49 U.S.C. 32901(a)(18).

\1275\ 42 FR 38365 (July 28, 1977).

\1276\ Id.

\1277\ 42 FR 38362, 38365 (July 28, 1977).

Under this interpretation, NHTSA created five different criteria of functional performance, any one of which would qualify the vehicle as a non-passenger automobile. The first, and most obvious type, is an automobile designed for transporting more than ten individuals.\1278\ The four other criteria were used to identify automobiles designed primarily or chiefly for carrying property or a derivative of an automobile designed primarily for the transportation of property and included automobiles that: (1) provide temporary living quarters; (2) transport property on an open bed; (3) provide greater cargo-carrying than passenger-carrying volume; or (4) permit expanded use of the automobile for cargo-carrying purposes through the removal of seats by means installed for that purpose by the manufacturer or with simple tools, so as to create a flat, floor level surface extending from the forwardmost point of installation of those seats to the rear of the automobile's interior.\1279\ The first three of these criteria have remained static over time and are codified at 49 CFR 523.5(a)(2) through (4). The fourth criteria, for automobiles derived from an automobile designed primarily for the transportation of property, has expanded over time. Currently, section 523.5(a)(5) classifies as non- passenger as any automobile with at least three rows of designated seating positions as standard equipment and has foldable or pivoting seats that can be removed, stowed, or folded to create a flat, leveled surface that extends from the forward most point of installation (of the third-row seat) to the rear of the automobile's interior.

\1278\ 49 CFR 523.5(a)(1).

\1279\ 42 FR 38367 (July 28, 1977).

After conducting an analysis of the fleet and vehicle characteristics, NHTSA no longer believes that the criteria in section 523.5(a)(5) are in accordance with the best reading of the statute. NHTSA's analysis has indicated that many vehicles that qualify as non- passenger automobiles solely on this criterion (i.e., the automobile does not meet any of the other criteria to be a non-passenger automobile) would be classified more appropriately as passenger automobiles: the presence of a foldable, stowable, or removable third row seat is not a significant design characteristic indicating that a chief purpose for the vehicle is to transport property. However, NHTSA's analysis also indicates that there is a subset of vehicles currently classified as non-passenger automobiles based on this criterion for vehicles with three or more rows of seating that NHTSA believes should remain in the non-passenger automobile category because they have some chief design characteristics for transporting property not currently captured by section 523.5(a). To ensure that NHTSA's criteria for automobiles that chiefly or significantly are for transporting property effectuate the best reading of the statutory definitions, NHTSA is finalizing two changes to the criteria in section 523.5(a). First, NHTSA will remove the current criteria in section 523.5(a)(5) for vehicles with three or more rows. Second, the agency will add a new criterion premised on a performance-based light-duty work factor (LDWF) utility metric. These finalized changes are discussed in more detail below. (1) Automobiles With Three or More Rows of Seating

As referenced above, automobiles with at least three rows of designated seating positions as standard equipment qualify as non- passenger automobiles under section 523.5(a)(5) if the removal or stowing of foldable seats creates a flat, leveled cargo surface extending from the forwardmost point of installation of those seats to the rear of the automobile's interior. The original version of this provision in the 1977 final rule was for automobiles that had removable seats, such that the automobile permits expanded use of the automobile for cargo-carrying purposes. In explaining the rationale for creating the criteria, the 1977 final rule preamble stated:

[I]t is not the convertibility factor alone which results in passenger vans being classified as non-passenger automobiles. It is that factor together with the derivative nature of those vans . . . . [S]ince a passenger van is designed with the same chassis, springs, and suspension system as a cargo van, it is treated in the same way as a cargo van.\1280\

\1280\ 42 FR 38367 (July 28, 1977).

When 49 CFR 523.5(a)(5) was applied to the original CAFE reference fleet, it achieved its intended objective of identifying those derivative vehicles, where purchasers could have instead

opted for a “cargo” version of that vehicle. However, unlike the other regulations in section 523.5(a), the regulation at 523.5(a)(5) does not describe a chief non-passenger characteristic, but rather a passenger-based design feature that does not evidence a chief non- passenger characteristic when applied to the current automobile fleet. The automobile fleet of the late 1970s was fundamentally different from the automobile fleet being manufactured and sold currently; there are no “cargo van” derivatives “designed with the same chassis, springs, and suspension system” in the present-day light-duty fleet. The regulatory text at 523.5(a)(5) applied to the late-1970s fleets accommodated the derivative vehicles as they existed at the time.

Regarding the current fleet, meeting the criterion in section 523.5(a)(5) is not enough to indicate that the automobile is not “manufactured primarily” for carrying passengers. In fact, the presence of at least three rows of designated seating positions indicates the opposite because having three rows of designated seating positions is a significant feature indicating that a primary purpose of that automobile is for carrying numerous passengers. NHTSA received no substantive comments specifically regarding section 523.5(a)(5). Accordingly, NHTSA will remove 49 CFR 523.5(a)(5) as a non-passenger classification criterion beginning with MY 2030. (2) Light-Duty Work Factor

With the removal of the expanded use criterion for vehicles with three or more rows of seating, NHTSA recognizes that some automobiles that have significant functional characteristics for the transportation of property would be classified as passenger automobiles unless NHTSA were to make further amendments to the criteria in section 523.5. To address this, NHTSA proposed a new criterion for classification as a non-passenger automobile. While the criterion NHTSA is removing for vehicles with three or more rows of seating is based primarily on a passenger-carrying design element (three rows of seats), in the NPRM, NHTSA proposed a new non-passenger automobile pathway that could be described independent of vehicle construction, platform, equipment, materials, or passenger-based metrics (such as rated cargo load \1281\ or seating arrangements). This new performance-based utility attribute, which NHTSA is referring to as the light-duty work factor (LDWF), would be determined based on a light-duty vehicle's ability to transport property via its payload and towing capacities. Performance-based standards preclude design or technology obsolescence by only prescribing a target without guidance or restriction on how it should be achieved.

\1281\ Per 49 CFR 571.110 S.3, rated cargo load can be calculated as the vehicle capacity weight (payload capacity) minus 68 kg (150 lbs.) times the vehicle's designated seating capacity.

NHTSA developed an analysis fleet specifically for the LDWF analysis, referred to as the LDWF analysis fleet. Beginning with the full MY 2024 non-passenger fleet, NHTSA created the LDWF analysis fleet by removing vehicles that qualified as non-passenger automobiles via any of the following pathways:

Transport more than 10 persons.

Provide temporary living quarters.

Transport property on an open bed.

Provide, as sold to the first retail purchaser, greater cargo-carrying than passenger-carrying volume.

Has either 4WD or a GVWR of more than 6000 lbs., and meets all four of the following criteria: \1282\

\1282\ These sub-bullets reflect the finalized changes to criteria for off-highway capability, which are discussed in detail in preamble Section VI.B.1.b and Final TSD Chapter 2.7.

[cir] Approach angle of not less than 28 degrees [cir] Breakover angle of not less than 14 degrees [cir] Departure angle of not less than 20 degrees [cir] Running clearance of not less than 20 centimeters

The agency opted to omit vehicles that qualified via these alternative non-passenger pathways because their designs contained other non-passenger characteristics or off-highway features that could skew the results of an analysis intended to evaluate whether a vehicle was designed chiefly for enhanced property-transporting utility. The remaining vehicles were subject to the LDWF analysis to evaluate an appropriate formula and threshold for the work factor.

In performing the fleet analysis to determine at what threshold of LDWF a vehicle would qualify as a non-passenger vehicle, NHTSA recognized that many vehicles could be specified with or without a trailering package (also commonly referred to as a “tow package” or “towing package”). These packages can range from minor changes, such as the inclusion of trailer wiring and a tow hitch, to more significant changes, such as higher capacity cooling packages, an enhanced suspension, a different final drive ratio, or reinforced driveline components. These changes do not significantly impact the powertrain or 2-cycle fuel economy of the base vehicle. In other words, trailering packages unlock utility that the powertrain and vehicle platform are already designed to provide. Therefore, in establishing the LDWF analysis fleet, NHTSA assumed that for a vehicle that would qualify as a non-passenger automobile via the LDWF criterion when specified with its trailering equipment, manufacturers would in the future not remove trailering capability as standard equipment on a vehicle that is otherwise designed to include it. These maximum available towing capacities for each vehicle in the LDWF analysis fleet were applied to the dataset used in the analysis.\1283\

\1283\ See Non-Passenger_FRM_Analysis.xlsx, Docket No. NHTSA- 2025-0491, tab “Existing Reg Classification,” column “Max Spec Tow Capacity (lb.).”

NHTSA proposed to calculate LDWF as the weighted sum of a vehicle's payload and towing capacities \1284\ and prescribed a minimum threshold for this non-passenger criterion based on extensive analysis. In determining appropriate weighting for payload and towing capacity in the LDWF calculation, NHTSA considered the vehicle design considerations and property-transporting capabilities of payload capacity versus towing capacity. Designing for a higher payload capacity includes considerations for axle, frame, suspension, wheel, and tire capacities. These higher capacity components add weight to the vehicle and, when combined with the additional payload capacity, may require only modest enhancements to the powertrain and driveline to maintain performance and utility characteristics. In contrast, designing for a higher towing capacity includes considerations for pulling, including frame reinforcements to resist trailer forces acting opposite the direction of motion, increases to powertrain torque and power, and reinforcing driveline components to handle the additional torque. There is also a modest consideration for payload increases when considering increases to towing capacity due to a trailer's tongue weight.\1285\ NHTSA ultimately

concluded that, in addition to the more expansive design considerations, towing capacity is a more effective means of providing cargo-transporting utility. Accordingly, NHTSA proposed a higher weighting for towing capacity when determining the LDWF.\1286\

\1284\ Towing capacity in the NPRM was proposed to be calculated as Gross Combined Weight Rating (GCWR) minus Gross Vehicle Weight Rating (GVWR).

\1285\ SAE, Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating and Trailer Weight Rating, SAE Standard J2807_202411, SAE International: Warrendale, PA (2024), available at: https://doi.org/10.4271/J2807_202411 (accessed: June 5, 2026).

\1286\ The proposed weighting in the NPRM was \2/3\ of towing capacity and \1/3\ of payload capacity, with a threshold of greater than or equal to 5500, calculated in pounds.

Comments received by NHTSA in support of the LDWF supported the NPRM position that towing and payload are better indicators of a vehicle's ability to provide non-passenger utility than the functional ability regulation that it is replacing.\1287\ Some commenters that provided constructive criticisms or suggestions to improve the LDWF proposal supported NHTSA's attempt to refocus non-passenger criteria on various combinations of capability, utility, statutory alignment, and real-world usage.\1288\ Other commenters in broad support of reclassification did not provide substantive comment specific to the LDWF.

\1287\ PMI, Docket No. NHTSA-2025-0491-5001-A2, at 45.

\1288\ Ford, Docket No. NHTSA-2025-0491-5821-A1, at 1-5; Toyota, Docket No. NHTSA-2025-0491-5997-A1, at 5-8, 10.

The agency received numerous comments containing criticisms of and suggestions to improve the LDWF proposal. Many commenters stated that the weighting scheme proposed in the NPRM for towing versus payload resulted in payload values so inconsequential that the agency may as well base the LDWF only on towing capacity.\1289\ Commenters criticized the LDWF threshold for being “arbitrarily defined,” suggesting that a vehicle capable of towing 5,000 pounds is “highly capable.” \1290\ Some commenters also stated their belief that NHTSA made improper use of GCWR in the context of towing capacity for the LDWF.\1291\ These comments largely recommended that the agency instead use the methodology specified in the consensus industry standard for determining GCWR and TWR, SAE J2807.\1292\ A subset of these commenters cautioned that while SAE J2807 is accepted by industry and synonymous with manufacturer tow ratings across a range of brands and models, it is not currently used across all brands and models, and that, if NHTSA were to adopt SAE J2807, sufficient time would be needed for some manufacturers to comply.\1293\ Commenters also expressed concern regarding NHTSA offsetting the LDWF threshold by 200 pounds to 5300 in the curve-setting analysis while leaving the regulatory threshold at 5500. Specifically, commenters stated that it implied an expectation or requirement for redesigns without sufficient notice.\1294\ Finally, commenters expressed concern about burdensome reporting requirements as a result of this new non-passenger automobile regulatory pathway.\1295\ This last topic regarding compliance reporting as it relates to the definition for curb weight is addressed in a later paragraph of this section.

\1289\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 8, - A2 at 24-25; Stellantis, Docket No. NHTSA-2025-0491-5968-A1, at 7-8; Ford, Docket No. NHTSA-2025-0491-5821-A1, at 1-3.

\1290\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 8; Stellantis, Docket No. NHTSA-2025-0491-5968-A1, at 7- 8, -A2 at 26; Ford, Docket No. NHTSA-2025-0491-5821-A1, at 2; Toyota, Docket No. NHTSA-2025-0491-5997-A1, at 3, 6, 8, 10.

\1291\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 8-9, -A2 at 25-27.

\1292\ SAE, Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating and Trailer Weight Rating, SAE Standard J2807_202411, SAE International: Warrendale, PA (2024), available at: https://doi.org/10.4271/J2807_202411 (accessed: May 28, 2026).

\1293\ Porsche, Docket No. NHTSA-2025-0490-0044-A1, at 2.

\1294\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 6.

\1295\ Nissan, Docket No. NHTSA-2025-04915857-A1, at 7.

NHTSA recognizes that GCWR can conflate the payload and towing capabilities of a vehicle, particularly on high-towing capable vehicles. Because NHTSA intends to consider the LDWF inputs separately (i.e., in the case of payload and towing, how much payload a vehicle can carry when not towing, and how much a vehicle can tow when at a minimum operating payload), NHTSA has concluded that this method for determining towing capacity is not suitable. The agency agrees that SAE J2807 is a more objective, industry-accepted, test-based methodology for evaluating towing capacity. Therefore, NHTSA is using TWR defined in accordance with SAE J2807 in the finalized provisions for the new LDWF pathway. Many U.S. and Japanese auto manufacturers have well- documented use of SAE J2807 for their tow ratings dating back to at least 2015.\1296\ NHTSA recognizes that not all manufacturers currently utilize SAE J2807 when specifying their tow ratings. The docketed analysis spreadsheet \1297\ was updated to reflect manufacturer maximum tow ratings directly, with links to the source information for each vehicle provided. Reporting TWR in accordance with the definition in SAE J2807 is necessary only for light-duty vehicles qualifying as non- passenger automobiles via the LDWF regulatory pathway, and there is no requirement for manufacturers to adhere to SAE J2807 across their entire fleet. Given SAE J2807's widespread acceptance and industry familiarity, NHTSA believes the two-year delay in the implementation of the changes at 49 CFR 523.5, to MY 2030, provides sufficient notice.

\1296\ Ram Trucks, Ram Truck Towing Capacity Guide (2026), available at: https://www.ramtrucks.com/towing/towing-capacity-guide.html?msockid=217fa4f6c78b68543fb0b3d6c626694f (accessed: June 5, 2026). 2024 Ford RV & Trailer Towing Guide, Docket No. NHTSA- 2025-0491-XXXX (new docket id); Honda, Docket No. NHTSA-2025-0491- 6013-A1, at 5.

\1297\ See Non-Passenger_FRM_Analysis.xlsx, Docket No. NHTSA- 2025-0491, tab “Existing Reg Classification.”

NHTSA also acknowledges that payload and towing capacity were not weighted commensurately in the NPRM. For this final rule, the agency evaluated a range of weighting combinations, including the removal of payload capacity. In these evaluations, NHTSA recognized that because maximum payload values are relatively small compared to TWR values, the percent change of increasing either by equal amounts is significantly higher for payload. For example, if a vehicle had a 1,600-pound maximum payload capacity and a 5,000-pound TWR, increasing each by 100 pounds would constitute a 6.25 percent increase in payload capacity and only a two percent increase in towing capacity. Through analysis, NHTSA determined that removing the weighting on payload capacity and TWR when calculating the LDWF effectively places higher significance on TWR while still providing a significant contribution from payload. Because both LDWF input parameters are weighted equally, the formula can be simplified to the unweighted sum of the payload capacity and TWR. In Final TSD Chapter 2.7.2.3.4, NHTSA provides the complete analysis for setting the LDWF threshold, and the supporting data can be found in the rule docket.\1298\ Unlike the NPRM, NHTSA did not apply an offset between the curve-setting LDWF threshold and the regulatory LDWF threshold. As previously discussed, there is no requirement or necessity for redesigns as a result of the classification changes, nor do the changes alter the inherent utility of the vehicles impacted by the classification change. That said, NHTSA

provides the two-year delay in the implementation of the changes at 49 CFR 523.5, to MY 2030, in this final rule.

\1298\ See Non-Passenger_FRM_Analysis.xlsx, which can be found in the rulemaking docket (NHTSA-2025-0491) in tab LDWF_Analysis for data and tabs LDWF Histogram and TWR Survival Analysis for figures.

In response to the claims of regulatory burden with the inclusion of the LDWF pathway, beginning with MY 2030, TWR is the only additional metric that manufacturers must provide, and the number of nameplates that need to provide non-passenger compliance metrics is significantly reduced.

Final TSD Chapter 2.7 provides the complete final rule analysis. Both the Final TSD Chapter 2.7 and preamble Regulatory Text provide the LDWF formula and threshold.\1299\

\1299\ The LDWF will be calculated as the sum of TWR and payload capacity, with a threshold of greater than or equal to 8,500, calculated in pounds.

In connection with the finalized addition of the LDWF, NHTSA will update its definition of curb weight and add two additional definitions for “nominal tank capacity” and “optional equipment,” terms used in determining curb weight.\1300\ NHTSA is changing the definition of curb weight and defining the additional terms to provide clarity regarding how NHTSA would test a vehicle to determine whether it meets the LDWF or off-road criteria for non-passenger automobiles. The discussion about changes to the definition of curb weight is discussed in preamble Section VI.B.4.

\1300\ Discussed in more detail in preamble Section VI.B.4.

Under EPCA, as amended by EISA, manufacturers are afforded several compliance flexibilities that can be used to achieve compliance with CAFE standards. While some of these flexibilities are provided to manufacturers by statute, such as the ability to carry forward and backward credits earned from over-complying with a CAFE standard in a given model year,\1301\ others are provided by regulations issued at NHTSA's discretion. Credit trading among manufacturers is one flexibility that the statute authorizes but does not mandate. Credit trading refers to the ability of manufacturers or persons to sell credits to, or purchase credits from, another manufacturer.\1302\ EISA gave NHTSA discretion to establish by regulation a CAFE credit trading program to allow credits to be traded between vehicle manufacturers.\1303\ While establishing the credit trading program is discretionary, it is also limited by statute. Total oil savings must be preserved when credits are traded, and traded credits are not permitted to be used to meet the MDPCS.\1304\ Under this discretionary authority, NHTSA established a credit trading program in its 2009 final rule, permitting manufacturers to trade credits earned in MY 2011 and later.\1305\ Under NHTSA's regulations, traded credits are subject to an “adjustment factor” to ensure total oil savings.\1306\

\1301\ 49 U.S.C. 32903(a).

\1302\ 49 CFR 536.3(b)(12).

\1303\ 49 U.S.C. 32903(f).

\1304\ 49 U.S.C. 32903(f)(1) and (2).

\1305\ 74 FR 14206 (Mar. 30, 2009).

\1306\ 49 CFR 536.4(c).

NHTSA has observed, in recent years, that credit trading increasingly has been used by manufacturers of ICE vehicles to purchase credits from manufacturers of alternative fueled vehicles. As fuel economy standards increase, manufacturers generally look for the most cost-effective means of compliance. As standards have increased to levels unattainable for ICE vehicles, credit trading has become an increasingly more attractive means of satisfying CAFE requirements. This situation is due, in part, to EV manufacturers earning credits that are not representative of real-world fuel savings. The fuel economy values for EVs have been artificially high, resulting from the fuel content factor multiplier in the PEF \1307\ and EV manufacturers' generating FCIVs for AC efficiency and OC technologies that are not representative of real-world fuel savings.\1308\ As a result, EV manufacturers have been earning an abundance of credits. Under NHTSA's credit trading program, EV manufacturers can sell their credits to ICE vehicle manufacturers, effectively subsidizing the production of EVs. This was never NHTSA's intention in establishing a credit trading program because it creates market distortion that undermines EPCA's overarching purposes.

\1307\ In DOE's final rule (89 FR 22041, Mar. 29, 2024), DOE explained that “by significantly overvaluing the fuel savings effects of EVs in a mature EV market with CAFE standards in place, the fuel content factor [in the PEF] will disincentivize both increased production of EVs and increased deployment of more efficient ICE vehicles,” which DOE concludes “results in higher petroleum use than would otherwise occur.”

\1308\ In EPA's Apr. 18, 2024, final rule (89 FR 27842), EPA noted that EVs are “receiving a windfall of credits [for AC efficiency technologies] that fails to correspond to any real-world reduction in vehicle emissions” and that there is “no technical basis for providing BEVs with off-cycle credits.”

In the NPRM, NHTSA proposed to end credit trading by MY 2028, with MY 2027 being the last year in which manufacturers can use traded credits for CAFE compliance. As discussed below, NHTSA is finalizing a change to end trading of credits generated after MY 2027. This is a slight change from the proposal in that manufacturers may still trade credits earned through MY 2027 to be used up to five model years into the future (e.g., credits earned in MY 2027 may be traded and used through MY 2032). Because NHTSA is finalizing amended standards that, as required by statute, do not consider alternative fueled vehicles or the use of compliance credits, NHTSA continues to believe that manufacturers of ICE vehicles will be able to meet CAFE standards without credit trading, thus minimizing any impacts on manufacturers' decisions about what vehicles and technologies to offer in the marketplace.\1309\ In the NPRM, NHTSA did not propose any changes to how manufacturers may transfer earned credits between their different compliance fleets, such as between their domestic passenger car and non-passenger car fleets, as this form of credit transfer is permitted explicitly by statute.

\1309\ 49 U.S.C. 32902(h).

In the NPRM, NHTSA sought comment on this proposal, including on its assumptions about manufacturers' compliance pathways exclusive of credit trading as a compliance option. NHTSA also sought comment on the extent to which the presence of credits changed manufacturer compliance behavior and on the value of credits now that the civil penalty rate has been updated by law. NHTSA did not receive any comments related to the value of credits with the updated civil penalty rate.

NHTSA received some comments in support of removing the credit trading program. The SEMA, PMI, and AFPM supported the removal of the credit trading program as proposed in the NPRM, asserting that the program has created a market distortion.\1310\ SEMA stated that structural reforms to the CAFE program, such as changes to credit trading, will “better reflect real-world vehicle attributes and compliance pathways, which will improve transparency and predictability for manufacturers and downstream industries.” \1311\ PMI commented that ending the credit trading program “is necessary to stop the market distortion that results from existing and past [fuel

economy] standards.” \1312\ AFPM said that “[t]hese transfers do not conserve petroleum; they merely enable paper compliance. By ending inter-company trading, the agency restores fuel economy as the primary pathway for meeting CAFE obligations.” \1313\

\1310\ SEMA, Docket No. NHTSA-2025-0491-5891, at 1; PMI, Docket No. NHTSA-2025-0491-5001-A1, at 3; AFPM, Docket No. NHTSA-2025-0491- 5964-A2, at 22.

\1311\ SEMA, Docket No. NHTSA-2025-0491-5891, at 1.

\1312\ PMI, Docket No. NHTSA-2025-0491-5001-A1, at 3.

\1313\ AFPM, Docket No. NHTSA-2025-0491-5964-A1, at 5.

NHTSA also received several comments asking NHTSA to retain the credit trading program. The Alliance, Honda, Attorneys General, Ferrari S.p.A. and Ferrari North America, Inc. (Ferrari), Hyundai, JLR, Kia, MEMA, NRDC et al., Nissan, Plug In America (PIA), Porsche, ME DEP, Volkswagen, and ZETA oppose the elimination of the credit trading program because the program allows flexibility as part of compliance plans or in unanticipated market conditions or supply chain disruptions.\1314\ Ferrari, MEMA, NRDC et al., ME DEP, and ZETA oppose the elimination of the credit trading program because removing it would disadvantage manufacturers' investments in other compliance strategies.\1315\ NRDC et al., China WTO/TBT, and ZETA said NHTSA is required to consider reliance interests engendered by the program prior to eliminating it.\1316\

\1314\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 11; Honda, Docket No. NHTSA-2025-0491-6013, at 8; Attorneys General, Docket No. NHTSA-2025-0491-6064-A2, at 103; Ferrari, Docket No. NHTSA-2025-0491-5062, at 4; Hyundai, Docket No. NHTSA-2025-0491- 4972, at 2; JLR, Docket No. NHTSA-2025-0491-5196, at 4; Kia, Docket No. NHTSA-2025-0491-5123, at 3; MEMA, Docket No. NHTSA-2025-0491- 5989, at 12; NRDC et al., Docket No. NHTSA-2025-0491-5928-A1, at 13- 14; Nissan, Docket No. NHTSA-2025-0491-5857, at 4; PIA, Docket No. NHTSA-2025-0491-4955, at 1; Porsche, Docket No. NHTSA-2025-0490- 0044, at 3; ME DEP, Docket No. NHTSA-2025-0490-0026, at 4-5; Volkswagen, Docket No. NHTSA-2025-0491-5036, at 2; ZETA, Docket No. NHTSA-2025-0491-6039-A1, at 13-15.

\1315\ Ferrari, Docket No. NHTSA-2025-0491-5062, at 4; MEMA, Docket No. NHTSA-2025-0491-5989, at 12; NRDC et al., Docket No. NHTSA-2025-0491-5928-A1, at 14; ME DEP, Docket No. NHTSA-2025-0490- 0026, at 4-5; ZETA, Docket No. NHTSA-2025-0491-6039, at 13-14.

\1316\ NRDC et al., Docket No. NHTSA-2025-0491-5928-A1, at 14; China WTO/TBT, Docket No. NHTSA-2025-0491-5056, at 3; ZETA, Docket No. NHTSA-2025-0491-6039-A1, at 13-15.

ME DEP commented that eliminating the credit trading program would disadvantage certain manufacturers with respect to investments they have made in credit-based compliance pathways.\1317\ NRDC et al., ZETA, an individual commenter, and PIA noted that removing these credits will discourage EV production and weaken the U.S. auto industry's ability to compete globally.\1318\ An individual commented, “This widens the technological gap between U.S. companies and global competitors. It threatens both export competitiveness and long-term market share in a rapidly electrifying global industry.” \1319\

\1317\ ME DEP, Docket No. NHTSA-2025-0490-0026, at 4-5.

\1318\ NRDC et al., Docket No. NHTSA-2025-0491-5928-A1, at 14; ZETA, Docket No. NHTSA-2025-0491-6039-A1, at 13-14; Laura Georgi, Docket No. NHTSA-2025-0491-6028; PIA, Docket No. NHTSA-2025-0491- 4955, at 1.

\1319\ Ryan Saunders, Docket No. NHTSA-2025-0491-5051, at 1.

China WTO/TBT commented that new manufacturers lack historical credit accumulation and thus cannot obtain compliance buffers through trading, which will increase their initial compliance costs and the difficulty entering the market.\1320\ ZETA, NRDC et al., and Porsche commented that eliminating the credit trading program will harm consumer choice, by eliminating a pathway that Manufacturers use to offset less fuel-efficient vehicles.\1321\ An anonymous commenter stated that eliminating credit trading will raise costs of compliance.\1322\

\1320\ China WTO/TBT, Docket No. NHTSA-2025-0491-5056, at 3.

\1321\ ZETA, Docket No. NHTSA-2025-0491-6039-A1, at 12; NRDC et al., Docket No. NHTSA-2025-0491-5928-A1, at 14; Porsche, Docket No. NHTSA-2025-0490-0044, at 3.

\1322\ Anonymous, Docket No. NHTSA-2025-0491-0033, at 1.

Attorneys General, ZETA, an individual commenter, and the Alliance commented that NHTSA has not provided sufficient reasoning or evidence to support its decision to eliminate the program.\1323\ The Alliance elaborated that NHTSA is already addressing concerns about EVs creating market distortions through setting standards that do not consider EVs, and that making changes to credit trading is redundant.\1324\ ZETA also commented that NHTSA cited, in its reasoning for proposing to end credit trading, artificially high fuel economy values for EVs resulting from factors that it states that NHTSA is proposing to end.\1325\ Attorneys General stated that NHTSA failed to consider important aspects of the proposed change, failed to consider alternatives, and failed to consider serious reliance interests when it proposed eliminating the credit trading program, which purportedly are “hallmarks of an arbitrary and capricious agency action that renders such actions unlawful under the APA.” \1326\

\1323\ Attorneys General, Docket No. NHTSA-2025-0491-6064, at 6; ZETA, Docket No. NHTSA-2025-0491-6039-A1, at 12; Kharisma Montes de Oca, Docket No. NHTSA-2025-0491-4552, at 1; The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 12.

\1324\ The Alliance, Docket No. NHTSA-2025-0491-5707-A2, at V-1.

\1325\ ZETA, Docket No. NHTSA-2025-0491-6039, at 14. NHTSA notes that while ZETA stated that NHTSA was proposing to end features that resulted in EVs having artificially high fuel economy values, DOE sets the PEF for EVs and EPA established the FCIV program that included BEVs until EPA issued its 2024 final rule (89 FR 27842) that prevents EVs from generating FCIVs starting in MY 2027. It appears ZETA misunderstood the difference between NHTSA's analysis supporting the setting of fuel economy standards and how manufacturers' fuel economy values are calculated for compliance purposes.

\1326\ Attorneys General, Docket No. NHTSA-2025-0491-6064-A2, at 104.

Several commenters suggested that NHTSA should extend the effective date for eliminating credit trading and suggested alternate pathways that would not involve eliminating credit trading. The Alliance and Nissan recommend that, if NHTSA eliminates the credit trading program, the agency should defer its elimination until MY 2030 to provide additional lead time.\1327\ CALSTART recommended that, if NHTSA eliminates the credit trading program, the agency should defer its elimination until MY 2032.\1328\ Porsche and ZETA oppose NHTSA eliminating the credit trading program in MY 2028, the same model year that changes to vehicle classification are implemented.\1329\ Honda recommended that NHTSA continue the credit trading program with constraining mechanisms (e.g., volumetric or percentage limits on traded credits) rather than eliminating it.\1330\ They argue that a constraining mechanism would ensure that the “windfall” for EV-only manufacturers is mitigated without restricting the flexibility on which traditional manufacturers rely.

\1327\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 12; Nissan, Docket No. NHTSA-2025-0491-5857, at 4-5.

\1328\ CALSTART, Docket No. NHTSA-2025-0491-6042, at 4-5.

\1329\ Porsche, Docket No. NHTSA-2025-0490-0044, at 3; ZETA, Docket No. NHTSA-2025-0491-6039-A1, at 13-15.

\1330\ Honda, Docket No. NHTSA-2025-0491-6013, at 8.

NHTSA also received comments from the Alliance, Porsche, JLR, Nissan and ZETA requesting that, if the credit trading program were discontinued after MY 2027, credits earned through that model year be allowed to be carried forward up to five years.\1331\ The change these manufacturers requested would allow manufacturers to use credits that were earned in MY 2027 to be traded

and used through MY 2032. The Alliance also suggested either delaying elimination of the credit trading program to MY 2030 to provide additional lead time or permitting the trading of credits for three years after the program has ended.\1332\ CALSTART argued that NHTSA should allow credit generation and banking through at least MY 2031.\1333\ CALSTART argued that, to preserve the credibility of the credit market, NHTSA should be explicit about the mechanisms it will use to enforce fuel economy standards and the consequences of not complying with those standards.\1334\

\1331\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 12; Porsche, Docket No. NHTSA-2025-0490-0044, at 3; JLR, Docket No. NHTSA-2025-0491-5196, at 4; Nissan, Docket No. NHTSA-2025-0491-5857, at 4-5; ZETA, Docket No. NHTSA-2025-0491-6039, at 14-15.

\1332\ The Alliance, Docket No. NHTSA-2025-0491-5707, at 11-13.

\1333\ CALSTART, Docket No. NHTSA-2025-0491-6042, at 4-5.

\1334\ CALSTART, Docket No. NHTSA-2025-0491-6042, at 4-5.

After reviewing the comments received regarding the proposed changes to the credit trading program, NHTSA agrees that all credits earned in the CAFE program up through MY 2027 should be permitted to be used for up to five model years after the year in which they were earned, which is consistent with the timeframe prescribed by 49 U.S.C. 32903(a) for manufacturers to carry forward their own credits. Therefore, NHTSA is revising the proposed changes to the credit trading program for the final rule. NHTSA is finalizing the removal of credit trading from the CAFE program for credits earned in MY 2028 and beyond.

NHTSA is finalizing the removal of the credit trading program to correct market distortion. In the past, BEVs equipped with AC efficiency or OC technologies have generated an excessive number of CAFE credits due to the fleet average fuel economy calculation methodology that includes DOE's PEF. For example, one manufacturer, that produces and sells a large volume of BEVs earned a total of approximately 116 million CAFE credits \1335\ in its domestic passenger and light truck fleets in MY 2021. This manufacturer averaged CAFE compliance of 620.4 mpg to 959.5 mpg from MY 2019 to MY 2021 in its regulatory fleets due to DOE's PEF and the EPA compliance calculation, and it sold these credits to offset other manufacturers' low CAFE performance. These credit transactions undermine the energy conservation purpose of EPCA.\1336\

\1335\ NHTSA, CAFE Public Information Center, Credit Status Report, available at: https://www.nhtsa.gov/corporate-average-fuel-economy/cafe-public-information-center (accessed: May 28, 2026).

\1336\ Roy, A., & Sriram, A., Tesla's Easy Money from Regulatory Credits Set to Dry Up Amid Weakening Sales, last revised: July 22, 2025, available at: https://www.reuters.com/business/autos-transportation/teslas-easy-money-regulatory-credits-set-dry-up-amid-weakening-sales-2025-07-22/ (accessed: May 28, 2026).

The agency recognizes that manufacturers have made investments in fuel-saving technologies, which they have factored into their future design and compliance plans. NHTSA also recognizes that manufacturers may have reliance interests in the credit trading program to fulfill their current CAFE compliance obligations. Ending credit trading within the CAFE program for credits earned in MY 2028 and beyond provides manufacturers adequate transition time before trading ends. Furthermore, the fuel economy standards in this final rule are achievable with ICE technologies without consideration of the factors NHTSA is prohibited from considering pursuant to 49 U.S.C. 32902(h), namely alternative fueled vehicles and the availability of credits.

Further, NHTSA notes that, though credits earned prior to MY 2028 may continue to be traded and used for up to five model years after they were earned, NHTSA expects the value of those credits to be significantly diminished. Not only does NHTSA believe that manufacturers will seek to meet the amended standards through actual fuel economy improvement through best practicable effort, but even so, with the updated $0.00 penalty rate, there is little to no benefit to manufacturers who may purchase those credits. Together, these factors significantly reduce the value of the credits to the manufacturer that would seek to sell them. 3. Technical Amendments To Remove References to EPA's Regulations for AC Efficiency and Off-Cycle Fuel Consumption Improvement Values

AC efficiency technologies are technologies that reduce the operation of, or the loads on, the vehicle engine by reducing AC usage. For example, the less frequently the AC compressor operates or the more efficiently it operates, the less load the AC compressor places on the engine, resulting in better fuel efficiency. AC efficiency technologies can include, but are not limited to, blower motor controls, internal heat exchangers, and improved condensers/evaporators. OC technologies are technologies that also reduce the operation of ICE engines, but they cover other areas of vehicle operation. Examples of OC technologies include thermal control technologies, high-efficiency alternators, and high-efficiency exterior lighting.\1337\

\1337\ 40 CFR 86.1869-12(b), Credit available for certain off- cycle technologies.

In its 2012 final rule, NHTSA issued regulations to align with EPA's provisions that allowed manufacturers to generate FCIVs for the adoption of AC efficiency and OC technologies beginning in MY 2017. EPA established the AC efficiency and OC programs to account for technologies that are not captured fully in the 2-cycle test procedures (FTP and HFET) that EPA uses to measure fuel economy for NHTSA's CAFE program. Under EPA's provisions, FCIVs generated by manufacturers are factored into each manufacturer's calculation of its average fuel economy for purposes of NHTSA's CAFE compliance.

Under EPA's current regulations, manufacturers are eligible to earn AC efficiency and OC FCIVs for all types of automobiles equipped with those technologies in their fleet through MY 2026. Starting in MY 2027, only ICE-powered automobiles are eligible to generate FCIVs, and the OC FCIV program is currently being phased out between MYs 2031-2033, with manufacturers no longer being able to generate OC FCIVs for MY 2033 and beyond.

As explained in Section II, NHTSA is now removing FCIVs from its standard-setting CAFE analysis starting in MY 2028 (i.e., NHTSA's model will no longer simulate manufacturers generating FCIVs that improve their fuel economy values for compliance). NHTSA is making this change in the analysis to ensure that it sets maximum feasible standards achievable without consideration of technology-specific standards.

Upon examination of NHTSA's existing regulations, NHTSA identified technical changes to remove references to EPA regulations pertaining to AC efficiency and OC FCIVs.

Accordingly, NHTSA proposed to remove the references to EPA's regulations regarding FCIVs from 49 CFR 531.6 and 49 CFR 533.6 because such references are unnecessary and created potential for confusion.

NHTSA received many comments on the AC and OC programs. The Alliance commented that they support the continuation of the AC efficiency and OC technology program under EPA's authority.\1338\ Honda, Ford, MECA, and MEMA support the program because the

technologies represent a cost-effective means of achieving real-world fuel economy benefits.\1339\ Hyundai and Kia commented that they have made significant investments to develop and apply the technologies to their fleets and support the continued use of the technologies for compliance.\1340\ Nissan commented that AC efficiency and OC benefits have been a part of the CAFE program since 2017 and are integral to manufacturers' product planning and further explained that removing the option to use these flexibilities would cause significant disruptions for manufacturers and reduce their ability to develop efficient and advanced technologies beyond MY 2033.\1341\ Porsche and Stellantis commented that they support the continued availability of AC efficiency and OC technologies as a compliance pathway independent of the impacts from EPA's rulemaking.\1342\ MEMA commented that NHTSA's language regarding AC efficiency and OC benefits in the NPRM is ambiguous and MEMA requested that NHTSA explicitly state in the final rule that any proposed changes to the treatment of AC efficiency and OC benefits are limited to analytical modeling and do not alter their eligibility for use in compliance.\1343\

\1338\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 12.

\1339\ Honda, Docket No. NHTSA-2025-0491-6013, at 8-9; Ford, Docket No. NHTSA-2025-0491-5821-A1, at 6-7; MECA, Docket No. NHTSA- 2025-0491-5331, at 7; MEMA, Docket No. NHTSA-2025-0491-5989, at 2-3.

\1340\ Hyundai, Docket No. NHTSA-2025-0491-4972, at 2; Kia, Docket No. NHTSA-2025-0491-5123, at 5-6.

\1341\ Nissan, Docket No. NHTSA-2025-0491-5857, at 5.

\1342\ Porsche, Docket No. NHTSA-2025-0490-0044, at 3-4; Stellantis, Docket No. NHTSA-2025-0491-5968, at 11.

\1343\ MEMA, Docket No. NHTSA-2025-0491-5989, at 11.

NHTSA received several comments supporting and opposing phasing out the AC efficiency and OC programs. ICCT and AFPM supported phasing out the AC and OC programs.\1344\ AFPM argued that these credits do not represent real-world petroleum conservation. ICCT argued that these technologies are already widespread and therefore do not need to be incentivized.

\1344\ ICCT, Docket No. NHTSA-2025-0491-5240-A1, at 9; AFPM, Docket No. NHTSA-2025-0491-5964-A2, at 20 and 27.

NHTSA responds to comments on the removal of FCIVs from the standard-setting CAFE analysis in Section II. In response to comments on removal of EPA's AC and OC programs, NHTSA does not have the authority to remove or alter EPA's AC and OC programs, and NHTSA did not propose any changes to EPA's AC and OC programs. EPCA, as amended by EISA, provides EPA with the authority to calculate the average fuel economy of a manufacturer's compliance fleet. NHTSA has no role in determining the testing and calculation procedures that are prescribed by EPA. NHTSA's goal in removing references to EPA's regulations from 49 CFR parts 531 and 533 is to avoid repeating measurement and calculation procedures determined by EPA. This change removes a potential for confusion and ensures alignment with EPA's regulations. NHTSA does not have the authority to establish its own set of calculation procedures that differ from EPA's procedures. As such, NHTSA is finalizing the removal of references to EPA's regulations for AC efficiency and OC FCIVs as proposed in the NPRM. 4. Modification of the Definition of Curb Weight and Manufacturer Reporting Requirements

NHTSA proposed changes to its reporting requirements for manufacturers in connection with the vehicle classification changes discussed above and is finalizing the proposal with certain revisions based on comments received and further consideration of the proposed reporting requirements.

In the NPRM, NHTSA proposed modifying its vehicle classification provisions under part 523. Specifically, NHTSA proposed modifications to several of the pathways manufacturers may use to classify a vehicle as a non-passenger automobile. NHTSA proposed removing the “expanded use” pathway under Sec. 523.5(a)(5) and proposed removing the axle clearance specification from the “off-highway pathway” under Sec. 523.5(b)(2), requiring that vehicles meet the remaining four criteria to qualify. NHTSA proposed implementing these changes beginning with MY 2028. To replace the “expanded use” pathway, NHTSA proposed adding a new, high-utility pathway into the non-passenger automobile fleet, beginning with MY 2028. This new pathway would be based on a performance-based utility attribute NHTSA refers to as the LDWF.

In the NPRM, NHTSA proposed calculating the LDWF value using several vehicle characteristics, including GCWR, which is the value manufacturers specify as the loaded weight of a combination vehicle, as well as GVWR and curb weight.

To support the new LDWF, NHTSA proposed updating its definition of curb weight and adding definitions for “nominal tank capacity” and “optional equipment,” which are two vehicle characteristics used in defining curb weight. NHTSA proposed modifying the curb weight definition to specify that curb weight is determined based on the actual weight of the vehicle at the time of first sale, including all optional equipment. These changes were proposed to provide clarity on how NHTSA would determine whether a particular vehicle meets the criteria for being classified as a non-passenger automobile under the “off-highway” and LDWF vehicle classification pathways.\1345\ The proposed change to the curb weight definition would ensure that every vehicle that a manufacturer reports as a non-passenger automobile would meet the requirements of the specific pathway in any configuration offered by the manufacturer.

\1345\ Curb weight is an integral part of the “off-highway” vehicle compliance pathway in Sec. 523.5(b).

In addition, NHTSA proposed revising its reporting requirements under part 537 to support the proposed vehicle classification modifications. The agency proposed removing reporting requirements specific to the “expanded use” pathway under Sec. 523.5(a)(5) and the axle clearance requirements of the “off-highway” pathway under Sec. 523.5(b)(2) for MY 2028 and beyond. NHTSA also proposed mandating GCWR as a required data field for all non-passenger automobiles for MY 2028 and beyond to support calculation of the LDWF but also to aid NHTSA in developing a better understanding of vehicle characteristics within the non-passenger automobile fleet.\1346\ NHTSA also included a requirement that manufacturers report curb weight for vehicles qualifying under the new LDWF pathway using NHTSA's proposed revised definition.

\1346\ Prior to this rulemaking, GCWR was only required to be reported for full-size pickup trucks.

NHTSA did not receive any substantive comments in support of its proposed modifications to manufacturers' reporting requirements. Nissan, Porsche, Stellantis, Ford, Mercedes-Benz, Volkswagen, Kia, and The Alliance expressed opposition to NHTSA's change in the definition of curb weight due to the increased reporting burden the change would precipitate.\1347\ In general, these commenters noted the burden

associated with tracking and reporting curb weight for many different vehicle configurations and requested that NHTSA not finalize any changes to its definition of curb weight. For example, Nissan commented that the use of curb weight in the LDWF calculation “creates an unreasonable and unnecessary analytical and administrative burden on [manufacturers].” \1348\ Nissan states that, for automakers, each buildable combination of a model type has an associated curb weight, which, Nissan states, means that for a given model, automakers would need to track and report on potentially hundreds of individual curb weights for every possible combination of subconfiguration, trim package, and option. Porsche's comment noted that within the Cayenne model there can be nearly 1 million buildable combinations and that weight differences of many of the combinations might be negligible. Porsche states that analyzing the weight differences would create complexity and add unnecessary costs. The other comments from industry expressed similar concerns and recommended that NHTSA continue referencing EPA's definition of curb weight in 40 CFR 86.1803-01.

\1347\ Nissan, Docket No. NHTSA-2025-0491-5857, at 7; Porsche, Docket No. NHTSA-2025-0490-0044, at 1; Stellantis, Docket No. NHTSA- 2025-0491-5968-A2, at 6; Ford, Docket No. NHTSA-2025-0491-5821-A1, at 1-3, Mercedes-Benz, Docket No. NHTSA-2025-0491-5854-A1, at 4; Volkswagen, Docket No. NHTSA-2025-0491-5036-A1, at 2; Kia, Docket No. NHTSA-2025-0491-5123, at 5; and The Alliance, Docket No. NHTSA- 2025-0491-5707-A1, at 8-9 and -A2, at 27-28.

\1348\ Nissan, Docket No. NHTSA-2025-0491-5857, at 7.

NHTSA has considered these comments and is finalizing a change to address manufacturers' concerns about the regulatory burden associated with the reporting requirements. To address these concerns, NHTSA is changing the reporting requirements in 49 CFR part 537 to clarify that manufacturers do not need to submit data for every vehicle configuration. NHTSA does not intend for manufacturers to include unique curb weights for each combination of subconfiguration, trim package, and option package. As commenters have stated, there are small variabilities in curb weight within models and trims that may not be necessary to report. NHTSA clarifies in this final rule that the curb weight required to be reported under 49 CFR 537.7(c)(5)(i)(F)(1) is the curb weight of the vehicle with the lowest LDWF in that subconfiguration.

In general, NHTSA's reporting requirements are based on how manufacturers would report fuel economy data to EPA for CAFE compliance purposes. That is, the level of granularity that is required for EPA reporting dictates the granularity for which data would be reported to NHTSA. It is NHTSA's understanding that data are reported to EPA at the vehicle subconfiguration level (i.e., meaning that each row of data reported to EPA is a vehicle subconfiguration, as defined at 40 CFR 600.002). NHTSA intends for its regulations to require that manufacturers submit data to NHTSA based on the reporting groupings reported to EPA (i.e., each row of data reported to NHTSA should align with a cohort of vehicles reported to NHTSA in a single row of data). Based on this intention, NHTSA is finalizing changes to part 537 to specify reporting for each vehicle configuration. Therefore, for each cohort of vehicle there would be a single data element reported for each type of information requested. In response to commenters' concerns, NHTSA is finalizing a change to require, for purposes of calculating LDWF, that manufacturers only report the curb weight of the vehicle with the lowest LDWF within that vehicle subconfiguration. Although this will often be the heaviest curb weight within the vehicle subconfiguration, to account for the possibility that the TWR may vary within the vehicle subconfiguration, NHTSA is specifying the data element based on the vehicle with lowest LDWF. This reporting requirement will allow NHTSA to conduct a more efficient audit of vehicle classification by identifying vehicles that exceed the criteria by the smallest margins.

NHTSA is also adding a definition of standard equipment to Sec. 523.2 to provide greater clarity because the term “standard equipment” is used in the definition of curb weight. NHTSA did not propose providing a definition as NHTSA believes the term is well- understood to mean, as defined in EPA's regulations at 40 CFR 86.1803- 01, “those features or equipment which are marketed on a vehicle over which the purchaser can exercise no choice.” However, to avoid any possible ambiguity, NHTSA is adding this definition to part 523.

NHTSA also received comments from Mercedes-Benz and the Alliance on when the curb weight definitional changes should take effect.\1349\ Both entities commented that, if NHTSA does finalize the changes to its curb weight definition, the agency should delay when those changes take effect. The commenters recommend setting the effective date to MY 2028 to align with the effective date of the other changes to vehicle classification.

\1349\ The Alliance, Docket No. NHTSA-2025-0491-5707-A1, at 9; Mercedes-Benz, Docket No. NHTSA-2025-0491-5854, at 4.

NHTSA has considered these comments and is finalizing changes such that reporting curb weight will go into effect for MY 2030 reporting, in line with the final rule's changes in vehicle classification that add the new “LDWF pathway.” The other situation in which the definition of curb weight in 523.2 is used is for purposes of determining whether a vehicle meets the criteria under the “off- highway pathway,” for which testing at curb weight is specified. In line with Mercedes-Benz and the Alliance's comment, NHTSA is finalizing the curb weight definitional change starting with MY 2028 in order to align NHTSA's regulations more faithfully with EPCA, which requires that every vehicle in the non-passenger automobile compliance category meet the prescribed classification criteria.

Ford expressed concern that “NHTSA will require manufacturers to provide vehicle weight information and off-highway criteria, regardless of which pathway is used.” \1350\ They commented that “data should only be required when it is necessary to demonstrate regulatory compliance.” Ford requested that NHTSA require manufacturers to report only data specific to the identified vehicle classification pathway.

\1350\ Ford, Docket No. NHTSA-2025-0491-5821, at 7.

NHTSA agrees with Ford's request for NHTSA to limit manufacturers' reporting requirements to only those data fields necessary for the vehicle classification pathway. It is not necessary to report all the possible data elements that could be used to classify a vehicle as a non-passenger automobile. Therefore, NHTSA is finalizing changes such that manufacturers are only required to report the data elements for the pathway used to qualify the vehicles as non-passenger automobile.

NHTSA is also replacing the GCWR reporting requirement with TWR for this final rule in line with the changes it is finalizing for the “LDWF pathway.” TWR is the value defined and used in SAE J2807, which is specified by the manufacturer as the maximum allowable weight of a loaded trailer for a specific vehicle model or configuration.1351 1352 NHTSA will require TWR because TWR information would be needed to determine whether an automobile qualifies as a non-passenger automobile under the LDWF criteria. Although NHTSA expects that TWRs will vary little, if any, within a

single-vehicle subconfiguration, to account for the possibility of variance, NHTSA is specifying that the manufacturers provide the TWR of the vehicle with the lowest LDWF if there are multiple TWRs within the subconfiguration. The reporting requirement for TWR will go into effect for MY 2030, in line with the vehicle reclassification changes.

\1351\ SAE, Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating and Trailer Weight Rating, SAE Standard J2807_202411, SAE International: Warrendale, PA (2024), available at: https://doi.org/10.4271/J2807_202411 (accessed: May 28, 2026).

\1352\ Further discussion on why NHTSA is moving forward with requiring TWR instead of GCWR can be found in preamble Section VI.B.1 and Final TSD Chapter 2.7.

NHTSA will also remove 49 CFR 523.5(a)(5) and 49 CFR 523.5(b)(2)(v) beginning with MY 2030. Additional details regarding their removal can be found in Section VI.B.1.b and in Final TSD Chapter 2.7. Due to these changes, starting in MY 2030, manufacturers will no longer be required to provide information related to these two regulations, which are described in 49 CFR 537.7(c)(5), paragraphs (c)(5)(i)(E) and (c)(5)(ii)(D), respectively.

In the NPRM, NHTSA proposed to make certain technical amendments through this rulemaking, which include amendments removing residual mentions of fuel efficiency standards for trailers; technical amendments removing reference to civil penalties for non-compliance with fuel economy standards; removing provisions applicable only to model years before MY 2022; and technical amendments correcting regulatory citations and incorporating minor spelling, grammatical, and formatting edits to 49 CFR parts 523, 531, 533, 536, 537 and 578. NHTSA will upload to the docket a redline version of the regulatory text showing the changes from this final rule.

NHTSA did not receive substantive comments on any of the technical amendments proposed in the NPRM. NHTSA is finalizing the technical amendments proposed in the NPRM in this final rule. In this final rule, NHTSA is also finalizing six additional technical amendments that were not included in the NPRM. First, NHTSA is modifying the civil penalty rate for non-compliance with fuel economy standards in part 578 to align with the updated statute set in Public Law 119-21, which was signed into law on July 4, 2025.\1353\ Second, NHTSA is finalizing a technical amendment to include a definition of vehicle subconfiguration to Sec. 537.8 that references EPA's definition used for CAFE compliance reporting. NHTSA is also finalizing two technical amendments to include the definition of footprint in parts 531 and 533 that reference back to NHTSA's definition of footprint in 523. Finally, NHTSA is finalizing technical amendments to add SAE J1100 NOV2009 to the list of incorporated materials in the new Sec. 523.11 and to update the title of SAE J1100 NOV2009 as it is referenced in the definition of passenger-carrying volume in Sec. 523.2.

\1353\ 49 U.S.C. 32912(b).

In November 2021, the United States Court of Appeals for the District of Columbia “vacate[d] all portions of the [2016 joint NHTSA and EPA] rule that apply to trailers.” \1354\ The underlying statute authorizes NHTSA to examine the fuel efficiency of and prescribe fuel economy standards for “work trucks and commercial medium-duty or heavy-duty on-highway vehicles.” 49 U.S.C. 32902(b)(1)(C); 49 U.S.C. 32902(k)(2). The court reasoned that trailers do not qualify as “vehicles” when that term is used in the fuel economy context because trailers are motorless and use no fuel. Truck Trailer Mfrs. Ass'n, Inc., 17 F.4th at 1200, 1204-08. Accordingly, the court held that NHTSA does not have the authority to regulate the fuel economy of trailers. Id. at 1208.\1355\

\1354\ Truck Trailer Mfrs. Ass'n, Inc. v. EPA, 17 F.4th 1198, 1200 (D.C. Cir. 2021).

\1355\ For similar reasons, the court also held that the statute authorizing EPA to regulate the emissions of “motor vehicles” does not encompass trailers. Id. at 1200-03. The court affirmed, however, that both agencies still “can regulate tractors based on the trailers they pull.” Id. at 1208 (emphasis original). Moreover, NHTSA is still authorized to regulate trailers in other contexts, such as under 49 U.S.C. chapter 301. See 49 U.S.C. 30102(a)(7) (defining “motor vehicle” to include “a vehicle . . . drawn by mechanical power”); Truck Trailer Mfrs. Ass'n, Inc., 17 F.4th at 1207 (“A trailer is `drawn by mechanical power.' ”).

On March 15, 2024, NHTSA published the final rule titled “Improvements for Heavy-Duty Engine and Vehicle Fuel Efficiency Test Procedures, and Other Technical Amendments.” (89 FR 18808). In that final rule, NHTSA removed portions of its regulations that were vacated by that decision. Because that final rule removed all the fuel efficiency standards for trailers and most of the mentions of those standards from its regulations, a residual mention of those standards remained in NHTSA's vehicle classification regulations at 49 CFR 523.10(a)(3). In the NPRM, NHTSA proposed to amend 49 CFR 523.10(a)(3) by deleting the sentence that mentions fuel efficiency standards for trailers. This rulemaking finalizes the deletion as proposed. 2. Technical Amendment To Remove Heavy-Duty Trailers From the List of Heavy-Duty Vehicle Regulatory Categories

On June 24, 2024, NHTSA published the final rule titled “Corporate Average Fuel Economy Standards for Passenger Cars and Light Trucks for Model Years 2027 and Beyond and Fuel Efficiency Standards for Heavy- Duty Pickup Trucks and Vans for Model Years 2030 and Beyond.” (89 FR 52540, June 24, 2024). In Section VII.C.8.e of that final rule,\1356\ NHTSA finalized the removal of “Heavy-duty trailers” from the list of four heavy-duty vehicle regulatory categories in 49 CFR 523.6(a). However, NHTSA inadvertently excluded the necessary changes from the final rule's amendatory text. In the NPRM, to align with its original intent as expressed in its 2024 final rule, NHTSA proposed to amend 49 CFR 523.6(a) introductory text by stipulating that heavy-duty vehicles are divided into three regulatory categories and removing paragraph (a)(4)--which lists heavy-duty trailers as a heavy-duty vehicle regulatory category--from 49 CFR 523.6(a). This rulemaking finalizes the amendment to the regulatory text as proposed. Along with this edit, NHTSA is also finalizing minor grammatical edits, without regulatory effect, to Sec. 523.7, Sec. 523.8, and Sec. 523.10, including amending Sec. 523.10 to remove an obsolete note from paragraph (a)(3) regarding trailers.

\1356\ 89 FR 52540, 52933 (June 24, 2024).

NHTSA is removing the mention of civil penalty payments for manufacturers that do not meet their fuel economy standards in the CAFE program from 49 CFR part 536. These amendments are to remove the mention of civil penalties from Sec. Sec. 536.5(d)(2) and (6), Sec. 536.9(e), Sec. 536.10(b); and to remove Sec. 536.7(b) through (d). 4. Additional Technical Amendments

NHTSA is incorporating minor technical amendments to 49 CFR parts 523, 531, 533, 536, and 537. These amendments are to correct regulatory citations and incorporate minor spelling, grammatical, and formatting edits. Specifically, NHTSA is incorporating the following technical amendments. a. Technical Amendments to Part 523

Although not in the NPRM, NHTSA is updating Sec. 523.1, without regulatory

effect, to correct the outdated authority citation and to make a grammatical edit. NHTSA is adding and removing text, correcting spelling errors, and incorporating other grammatical edits to clarify several definitions, including Basic vehicle frontal area, Breakover angle, Cargo-carrying volume, Electric vehicle, Emergency vehicle, Full-size pickup truck, Medium-duty passenger vehicle, Pickup truck, Temporary living quarters, Transmission configuration, Truck tractor, and Vocational vehicle (or heavy-duty vocational vehicle) in Sec. 523.2 and Sec. 523.3; and correcting a regulatory citation in Sec. 523.4. In addition, though it was not proposed in the NPRM, NHTSA is finalizing a very small change, without regulatory effect, to the definition of Base tire (for passenger automobiles, non-passenger automobiles, and medium-duty passenger vehicles), which references EPA's definition of standard equipment found in 40 CFR 86.1803-01. Because NHTSA is adding the identical definition of “standard equipment” used by EPA in 40 CFR 86.1803-01 to Sec. 523.2 in connection with its changes to the definition of curb weight, the reference to the EPA regulation within the definition of Base tire (for passenger automobiles, non-passenger automobiles, and medium-duty passenger vehicles) is no longer needed. NHTSA is also finalizing a technical change to the definition of passenger-carrying volume to update the title of SAE Surface Vehicle Recommended Practice J1100, Motor Vehicle Dimensions. Though not proposed in the NPRM, this change is being finalized as a technical amendment that has no regulatory impact. NHTSA is also adding SAE J1100 NOV2009 to the list of materials incorporated by reference in Sec. 523.11. b. Technical Amendments to Part 531

NHTSA is adding a definition of the term footprint to Sec. 531.4 that references back to NHTSA's definition of footprint in 523.2. NHTSA is removing requirements for past model years from Sec. 531.5 and making minor grammatical and organizational edits to streamline the section and improve readability. c. Technical Amendments to Part 533

NHTSA is adding a definition of the term footprint to Sec. 533.4 that references back to NHTSA's definition of footprint in 523.2. NHTSA is also finalizing minor grammatical edits and clarifying edits, without regulatory effect, to the definitions in Sec. 533.4 for Captive import and Limited product line. NHTSA is also correcting formatting errors in the text supporting equation 1 to Sec. 533.5(a). d. Technical Amendments to Part 536

NHTSA is finalizing minor clarifying edits, without regulatory effect to Sec. 536.1 and Sec. 536.3(b)(6); removing the definition of Light truck in Sec. 536.3(b); adding and removing text to clarify the definition of Trade in Sec. 536.3(b); adding and removing text to clarify the definition of Transfer in Sec. 536.3(b); correcting a capitalization error in Sec. 536.4(c); adding and removing text to clarify provisions in Sec. 536.4(a) through (c) and Equation 1 to Sec. 536.4(c); correcting a table heading in Table 1 to Sec. 536.4(c); renaming the title of Sec. 536.6; adding a new paragraph (a) to Sec. 536.6; changing the existing paragraph (a) to paragraph (a)(1) in Sec. 536.6 and making other edits to reorganize Sec. 536.6 for clarity and readability. NHTSA is also finalizing an edit to amend the title of Sec. 536.8 and make other minor grammatical edits to Sec. 536.8 and Sec. 536.9 e. Technical Amendments to Part 537

NHTSA is amending Sec. 537.4(b)(2) to add the term vehicle subconfiguration to the list of terms that are defined in 40 CFR part 600. NHTSA is correcting a spelling error in Sec. 537.4(b)(3) and a regulatory citation in Sec. 537.7(c)(7)(i).

NHTSA is also finalizing another technical amendment to part 537 that was not proposed in the NPRM, which updates the language in 49 CFR 537.6 (d)(4) regarding how manufacturers submit confidential reports and requests for confidentiality to NHTSA. NHTSA recently developed an online portal for receiving requests for confidential treatment. This new portal allows manufacturers to upload files required for part 512 requests for confidential treatment in one centralized location. NHTSA is now finalizing changes to Sec. 537.5 (d)(4) to replace the current language that directs manufacturers to submit confidential reports and requests for confidentiality to NHTSA on CD-ROM via mail. The technical amendment changes the language to direct manufacturers to use NHTSA's new CBI portal, which will align the regulatory text with current practice. 5. Technical Amendment To Modify the Civil Penalty for Non-Compliance With Fuel Economy Standards in Part 578

NHTSA is modifying the civil penalty rate, with no substantive effect, to reflect the rate set by Congress in Public Law 119-21, which was signed into law on July 4, 2025. This law amended EPCA's civil penalty rate for exceeding the applicable average fuel economy standard and set the civil penalty rate to $0.00 multiplied by each 0.1 of a mile a gallon by which the applicable average fuel economy standard exceeds the average fuel economy. The new $0.00 civil penalty rate is applicable to all model years for which NHTSA has yet to conclude compliance proceedings--which is MY 2022 and later. To align with 49 U.S.C. 32912(b) and 32912(c)(1)(B), NHTSA is amending 49 CFR 578.6(h)(2) to set the civil penalty rate to $0.00 for MY 2022 and later model years.

A. Executive Order 12866, “Regulatory Planning and Review”; Executive Order 13563, “Improving Regulation and Regulatory Review”; Executive Order 14192, “Unleashing Prosperity Through Deregulation”; and Executive Order 14219, “Ensuring Lawful Governance and Implementing the President's `Department of Government Efficiency' Deregulatory Initiative”

E.O. 12866, “Regulatory Planning and Review” (58 FR 51735, Oct. 4, 1993), reaffirmed by E.O. 13563, “Improving Regulation and Regulatory Review” (76 FR 3821, Jan. 21, 2011), provides for determining whether a regulatory action is “significant” and therefore subject to the OMB review process and to the requirements of the Executive Order. This action is a “significant regulatory action” under Section 3(f)(1) of E.O. 12866 because it is likely to have an annual effect on the economy of $100 million or more. Accordingly, NHTSA submitted this rulemaking to OMB for review, and any changes made in response to interagency feedback submitted via the OMB review process have been documented in the docket for this rulemaking. The estimated benefits and costs of this final rule are described above, and in the FRIA, located in the docket and on NHTSA's website.

E.O. 14192, “Unleashing Prosperity Through Deregulation” (90 FR 9065, Feb. 6, 2025), requires an agency, unless prohibited by law, to identify at least ten existing regulatory requirements to be repealed when the agency publicly proposes for notice and comment or otherwise promulgates a new significant regulatory rule. Section 3(c) of E.O. 14192 also requires that the total incremental costs associated with an agency's new regulations must, to the extent permitted by law, be offset by the elimination of costs associated with other previous regulations of the agency. This final rule is an E.O. 14192 deregulatory action and thus is not expected to generate net new incremental costs. The estimated cost savings of this final rule are detailed in FRIA Tables 1-3 and 1-4.

E.O. 14219, “Ensuring Lawful Governance and Implementing the President's `Department of Government Efficiency' Deregulatory Initiative” (90 FR 10583, Feb. 19, 2025) requires agency heads to review their regulations and identify any that, among other things, are based on anything other than the best reading of the underlying statutory authority or prohibition or that implicate matters of social, political, or economic significance that are not authorized by clear statutory authority. NHTSA has identified its CAFE standards issued in 2022 and 2024 as falling within an enumerated category of E.O. 14219. Specifically, as described in an interpretive rule published on June 11, 2025, NHTSA determined that the CAFE standards issued in 2022 and 2024 are not authorized by clear statutory authority. NHTSA is issuing this final rule to reset the CAFE standards and bring the CAFE program into compliance with relevant statutory requirements. NHTSA discusses compliance with relevant statutory requirements in Section V above.

To inform its development of the CAFE standards for MYs 2022-2031, and pursuant to NEPA, 42 U.S.C. 4321 et seq., and DOT Order 5610.1D, 90 FR 29621 (July 3, 2025), NHTSA prepared a Final SEIS to evaluate the potential environmental impacts of the CAFE standards and a reasonable range of alternatives. In revising the CAFE standards established in NHTSA's June 2024 final rule, NHTSA is making substantial changes to those examined in the 2024 Final EIS and, as such, prepared this Final SEIS to inform its amendment of MYs 2027-2031 CAFE standards. A commenter asserted that NHTSA failed to evaluate the full scope of its action because it assessed only the environmental impacts associated with MYs 2027-2031 CAFE standards.\1357\ As explained in the NPRM and further addressed in Chapter 1 (Purpose and Need for the Action) of the Final SEIS, the MY 2026 passenger car and light truck fleets have already been produced and are released for sale at the time of issuance of this final rule to amend MY 2022-2031 CAFE standards. As such, the Final SEIS analyzes environmental impacts associated only with the MY 2027-2031 CAFE standards and range of alternatives.

\1357\ NRDC et al., Docket No. NHTSA-2025-0491-5948, at 6-7.

The Final SEIS analyzes reasonably foreseeable impacts of the final rule on the potentially affected environment, which are discussed in proportion to their significance. It also discusses NHTSA's reasonable range of alternatives, including a No-Action Alternative and a Preferred Alternative, and other factors used in developing this final rule. The Final SEIS addresses mitigation measures considered as part of the environmental analysis.\1358\ NHTSA received many comments on the Draft SEIS. Comments regarding the scope and need for a NEPA analysis are addressed in Section V above, while those regarding the environmental analyses presented in the Draft SEIS are addressed in Appendix C of the Final SEIS.

\1358\ DOT Order 5610.1D, sec. 26.l (“Mitigation means measures that avoid, minimize, or compensate for environmental impacts caused by a proposed action or alternatives . . . . While NEPA requires consideration of mitigation, it does not mandate the form or adoption of any mitigation.”).

As explained in NHTSA's June 2025 interpretive rule, NHTSA “must not consider the fuel economy of dedicated automobiles; must consider dual-fueled automobiles to be operated only on gasoline or diesel fuel; and must not consider, when prescribing a fuel economy standard, the trading, transferring, or availability of credits under [49 U.S.C. 32903].” \1359\ NEPA, however, does not impose such constraints on analysis; instead, NEPA requires that Federal agencies consider the “reasonably foreseeable environmental effects of the proposed agency action.” \1360\ NHTSA's Final SEIS therefore presents results of an “unconstrained” analysis that considers manufacturers' potential use of CAFE credits and application of alternative fuel technologies (including PHEVs using their charge depleting fuel economy values, BEVs, and FCEVs) in order to disclose and allow consideration of real- world environmental consequences of the final rule and alternatives.\1361\

\1359\ Resetting the Corporate Average Fuel Economy Program; Interpretive Rule, 90 FR 24518, 24519 (June 11, 2025).

\1360\ 42 U.S.C. 4332(2); DOT Order 5610.1D, sec. 13.f.

\1361\ See Appendix D of the Final SEIS for a discussion of the full range of modeled electrified technologies.

NHTSA has considered the information contained in the Final SEIS as part of developing this final rule and in selecting the final standards.\1362\ This preamble and final rule constitute the agency's Record of Decision (ROD) for its promulgation of CAFE standards for MYs 2022-2031 passenger cars and light trucks. The agency has the authority to issue its Final SEIS and ROD simultaneously, pursuant to 49 U.S.C. 304a(b) and Section 14 of DOT Order 5610.1D. NHTSA has determined that simultaneous issuance is appropriate here because a separate 30-day waiting period is not required to address unresolved interagency disagreements or extraordinary public controversy that could otherwise affect the agency's final decision. Accordingly, neither the statutory criteria nor practicability considerations preclude issuing the combined documents. For additional information on NHTSA's NEPA analysis, please see the Final SEIS.

\1362\ The Final SEIS is available for review in the public docket for this action and in Docket No. NHTSA-2025-0491.

The CAA (42 U.S.C. 7401 et seq.) is the primary Federal legislation that addresses air quality. Under the authority of the CAA and subsequent amendments, EPA has established National Ambient Air Quality Standards (NAAQS) for six criteria pollutants, which are reviewed every five years.

The air quality of a geographic region is usually assessed by comparing the levels of criteria air pollutants found in the ambient air to the levels established by the NAAQS (also considering the other elements of a NAAQS: averaging time, form, and indicator). Concentrations of criteria pollutants within the air mass of a region are measured in parts of a pollutant per million parts (ppm) of air or in micrograms of a pollutant per cubic meter ([mu]g/m\3\) of air present in repeated air samples taken at designated monitoring locations using specified types of monitors. These ambient concentrations of each criteria pollutant are compared to the levels, averaging time, and form specified by the NAAQS to assess whether the region's air quality is in attainment with the NAAQS.

When the measured concentrations of a criteria pollutant within a geographic region are below those permitted by the NAAQS, EPA designates the region as an attainment area for that pollutant, while regions where concentrations of criteria pollutants exceed Federal standards are called non-attainment areas. Former non-attainment areas that are now in compliance with the NAAQS are designated as maintenance areas. Each State with a non-attainment area is required to develop and implement a State Implementation Plan (SIP) documenting how the region will reach attainment levels within the time periods specified in the CAA. For maintenance areas, the SIP must document how the State intends to maintain compliance with the NAAQS. EPA develops a Federal Implementation

Plan (FIP) if a State fails to submit an approvable plan for attaining and maintaining the NAAQS. When EPA revises a NAAQS, each State must revise its SIP to address how it plans to attain the new standard.

No Federal agency may “engage in, support in any way or provide financial assistance for, license or permit, or approve” any activity that does not “conform” to a SIP or FIP after EPA has approved or promulgated it.\1363\ Further, no Federal agency may “approve, accept or fund” any transportation plan, program, or project developed pursuant to title 23 or chapter 53 of title 49, U.S.C., unless the plan, program, or project has been found to “conform” to any applicable implementation plan in effect.\1364\ The purpose of these conformity requirements is to ensure that federally sponsored or conducted activities do not interfere with meeting the emissions targets in SIPs or FIPs, do not cause or contribute to new violations of the NAAQS, and do not impede the ability of a State to attain or maintain the NAAQS or delay any interim milestones. EPA has issued two sets of regulations to implement the conformity requirements:

\1363\ 42 U.S.C. 7506(c)(1).

\1364\ 42 U.S.C. 7506(c)(2).

(1) The Transportation Conformity Rule \1365\ applies to transportation plans, programs, and projects that are developed, funded, or approved under 23 U.S.C. (Highways) or 49 U.S.C. chapter 53 (Public Transportation).

\1365\ 40 CFR part 51, subpart T, and part 93, subpart A.

(2) The General Conformity Rule \1366\ applies to all other Federal actions not covered under the Transportation Conformity Rule. The General Conformity Rule establishes emissions thresholds, or de minimis levels, for use in evaluating the conformity of an action that results in emissions increases.\1367\ If the net increases of direct and indirect emissions exceed any of these thresholds, and the action is not otherwise exempt, then a conformity determination is required. The conformity determination can entail air quality modeling studies, consultation with EPA and State air quality agencies, and commitments to revise the SIP or to implement measures to mitigate air quality impacts.

\1366\ 40 CFR part 51, subpart W, and part 93, subpart B.

\1367\ 40 CFR 93.153(b).

During the public comment period, NHTSA received comments regarding the general impacts of the rulemaking on CAA goals, State SIP planning, and cooperative federalism. Commenters, including the NACAA, Minnesota state agencies, Connecticut Department of Energy and Environmental Protection (CT DEEP), Attorneys General, and Sabin et al., argued that reducing stringency of CAFE standards will increase criteria pollutants (such as NOX, VOCs, and PM2.5) and upstream emissions, jeopardizing States' and cities' abilities to attain or maintain the NAAQS.\1368\ These commenters argued that because mobile sources dominate the emission inventory in many non-attainment areas, the proposal creates an unfunded mandate forcing States to rely on costly, less effective controls on stationary sources. They stated this disrupts the CAA's “cooperative federalism” framework, where States rely on a strong federal floor for mobile source emission controls. NHTSA notes that the number of vehicle refueling events and the impacts of the emissions of certain criteria pollutants and their precursors will vary from area to area, depending on factors such as the composition of the local vehicle fleet and the amount of gasoline produced in the area. States consider emissions or air quality impacts in the context of SIP development for relevant NAAQS.

\1368\ NACAA, Docket No. NHTSA-2025-0491-5884, at 2, 5-8; Minnesota state agencies, Docket No. NHTSA-2025-0491-5847, at 2-4; CT DEEP, Docket No. NHTSA-2025-0491-5930, at 3-4; Attorneys General, Docket No. NHTSA-2025-0491-6064-A3, at 4; Sabin et al., Docket No. NHTSA-2025-0491-5808, at 2-6.

In addition, multiple State Attorneys General commented that NHTSA failed to examine the environmental justice implications of criteria pollution tied to upstream emissions from petroleum extraction and refining.\1369\ Other commenters raised specific programmatic concerns. ZETA asserted that NHTSA must consider existing EPA greenhouse gas standards in its baseline, rather than disregarding them due to a proposed rescission.\1370\ BGA argued that relaxing standards harms the domestic supply chain and auto sector employment.\1371\ NACAA urged a coordinated multi-pollutant approach with the EPA to maximize co- benefits, while other commenters argued conversely that utilizing criteria pollutant co-benefits to justify regulations drives up excess net costs.\1372\ Furthermore, NACAA warned that removing civil penalties creates compliance uncertainty that undermines the emissions assumptions used in State SIPs and suggested NHTSA explore an incentive-based alternative approach.\1373\

\1369\ Attorneys General, Docket No. NHTSA-2025-0491-6064, at 17-25.

\1370\ ZETA, Docket No. NHTSA-2025-0491-6039, at 5-6.

\1371\ BGA, Docket No. NHTSA-2025-0491-5931, at 2.

\1372\ NACAA, Docket No. NHTSA-2025-0491-5884, at 15; AEI, Docket No. NHTSA-2025-0490-0061, at 2, 9.

\1373\ NACAA, Docket No. NHTSA-2025-0491-5884, at 16.

As disclosed and evaluated in Chapter 4 (Air Quality) and Appendix F of the Final SEIS, NHTSA modeled the projected impacts of the alternatives on criteria pollutants and mobile source air toxics. Regarding comments asserting the agency failed to examine upstream emissions and related environmental justice implications, NHTSA notes that, as determined by the Supreme Court in Seven County Infrastructure Coalition v. Eagle County, Colorado, 605 U.S. ___ (2025), an agency is not required under NEPA to analyze upstream or other cumulative environmental impacts that fall outside its statutory authority. Because NHTSA's mandate under EPCA does not provide the authority to regulate upstream petroleum extraction or refining, analyzing these upstream impacts is not required. Furthermore, the Executive Orders that previously directed environmental justice analyses have been rescinded. Further discussion of the Seven County decision and the scope of the agency's impacts analysis can be found in the Final SEIS.

In response to the broader programmatic, baseline, and multi- pollutant comments, NHTSA emphasizes that this rulemaking is governed by EPCA, not the CAA. As previously discussed in Section V of this preamble, EPCA requires NHTSA to set maximum feasible average fuel economy standards by balancing four specific statutory factors: technological feasibility, economic practicability, the effect of other motor vehicle standards of the Government, and the need of the United States to conserve energy. While NHTSA consults with the EPA and properly considers existing, legally effective Federal emissions standards as “other motor vehicle standards of the Government,” EPCA does not authorize NHTSA to base its fuel economy standards on the objectives of ensuring local NAAQS attainment, minimizing State stationary-source control costs, or directly regulating environmental pollution. Finally, regarding the comments on civil penalties and incentives, NHTSA is bound by EPCA's specific statutory framework governing the assessment and collection of CAFE civil penalties, which does not grant the agency the authority to replace the penalty structure with the alternative compliance incentive programs. The finalized CAFE standards and associated program activities are not

developed, funded, or approved under 23 U.S.C. or 49 U.S.C. chapter 53. Accordingly, this final rule and associated program activities would not be subject to transportation conformity requirements.

During the public comment period, several commenters, including State environmental agencies (ME DEP, OR DEQ), NACAA, and the South Coast AQMD, expressed concern that the proposed rule alters the future emissions trajectories relied upon in SIPs.\1374\ Commenters noted that State transportation conformity determinations rely on the EPA's MOVES model, which incorporates existing CAFE assumptions.\1375\ They argued that changes to the vehicle standards could invalidate existing Motor Vehicle Emissions Budgets (MVEBs), create gaps between projected and allowable emissions, and potentially halt major transportation projects.

\1374\ ME DEP, Docket No. NHTSA-2025-0490-0026, at 6; OR DEQ, Docket No. NHTSA-2025-0491-5937, at 5; NACAA, Docket No. NHTSA-2025- 0491-5884, at 7-8, 11; South Coast AQMD, Docket No. NHTSA-2025-0490- 0064, at 2-5.

\1375\ NACAA, Docket No. NHTSA-2025-0491-5884, at 6.

While NHTSA acknowledges that State environmental and planning agencies utilize the EPA's MOVES model to establish MVEBs for their SIPs, and that States may need to update their planning models to reflect the revised Federal vehicle standards, this downstream modeling and SIP maintenance responsibility does not subject NHTSA's Federal rulemaking to transportation conformity. Because the agency's action does not fall under the statutory transportation planning provisions of title 23 or chapter 53 of title 49, U.S.C., transportation conformity requirements do not apply to this action.

Under the General Conformity Rule, a conformity determination is required where a Federal action would result in total direct and indirect emissions of a criteria pollutant or precursor in a non- attainment or maintenance areas equaling or exceeding the rates specified in 40 CFR 93.153(b)(1) and (2). As explained below, NHTSA's final rule would not result in direct or indirect emissions as defined in 40 CFR 93.152.

The General Conformity Rule defines direct emissions as “those emissions of a criteria pollutant or its precursors that are caused or initiated by the Federal action and originate in a non-attainment or maintenance area and occur at the same time and place as the action and are reasonably foreseeable.” \1376\ NHTSA's final rule establishes fuel economy standards for passenger cars and light trucks. It therefore would not cause or initiate direct emissions consistent with the meaning of the General Conformity Rule.\1377\

\1376\ 40 CFR 93.152.

\1377\ Dep't of Transp. v. Pub. Citizen, 541 U.S. 752, 772 (2004) (“The emissions from the Mexican trucks are not `direct' because they will not occur at the same time or at the same place as the promulgation of the regulations.”). NHTSA's final rule would establish fuel economy standards for MYs 2022-2031 passenger cars and light trucks; any emissions increases would occur in a different place and well after promulgation of the final rule.

Indirect emissions under the General Conformity Rule are “those emissions of a criteria pollutant or its precursors: (1) [t]hat are caused or initiated by the Federal action and originate in the same non-attainment or maintenance area but occur at a different time or place as the action; (2) [t]hat are reasonably foreseeable; (3) [t]hat the agency can practically control; and (4) [f]or which the agency has continuing program responsibility.” \1378\ Each element of the definition must be met to qualify as indirect emissions. NHTSA has determined, for purposes of general conformity, that emissions (if any) that may result from its fuel economy standards would not be caused by the agency's action, but rather would occur because of subsequent activities the agency cannot practically control. “[E]ven if a Federal licensing, rulemaking or other approving action is a required initial step for a subsequent activity that causes emissions, such initial steps do not mean that a Federal agency can practically control any resulting emissions.” \1379\

\1378\ 40 CFR 93.152.

\1379\ 40 CFR 93.152.

NHTSA received comments from organizations including the NRDC et al.\1380\ and South Coast AQMD \1381\ asserting that a general conformity determination is required. Commenters argued that the agency's own Draft SEIS identifies “reasonably foreseeable” increases in emissions (such as NOX and VOCs) that exceed the de minimis thresholds established in 40 CFR 93.153, such as the 10 tons- per-year threshold in the South Coast Air Basin. South Coast AQMD argued that because these emissions are a substantive result of the rulemaking, the categorical exemption for rulemaking does not apply. These commenters challenged NHTSA's position that it cannot control these emissions, arguing that because NHTSA sets the fleetwide fuel economy standards, the agency has continuing program responsibility and practical control over the emissions outcomes. Furthermore, NRDC argued that the Supreme Court's ruling in Department of Transportation v. Public Citizen does not exempt NHTSA from a conformity determination, asserting that unlike the regulations of the Federal Motor Carrier Safety Administration in that case, NHTSA's standards are intended by Congress to act as an emissions-reduction tool.

\1380\ NRDC et al., Docket No. NHTSA-2025-0491-5928-A2, at 113- 115.

\1381\ South Coast AQMD, Docket No. NHTSA-2025-0490-0064, at 2- 5.

NHTSA disagrees with the commenters' assertions that the projected emissions increases trigger a conformity determination. While the SEIS models potential criteria pollutant impacts for the purposes of NEPA, those projections do not equate to indirect emissions under the General Conformity Rule. EPCA requires NHTSA to set fleetwide average fuel economy standards for the CAFE program using performance-based standards. NHTSA is not authorized to dictate how manufacturers are to comply with the standards, nor may NHTSA require manufacturers to use specific technologies to achieve improved fuel economy in their fleets. Furthermore, NHTSA cannot control consumer purchasing or driving behavior, both of which can have a considerable effect on vehicle emissions of criteria pollutants. It is the combination of factors outside NHTSA's authority, such as manufacturers' decisions to apply fuel economy technologies and consumers' purchasing and driving behaviors, which determine the aggregate levels of criteria pollutant and precursor emissions.

For purposes of analyzing the environmental impacts of the alternatives considered under NEPA, NHTSA has necessarily made assumptions regarding all of these factors. NHTSA's Final SEIS projects that increases in air toxics and criteria pollutants would occur in some non-attainment areas under certain alternatives. However, the CAFE standards do not mandate specific manufacturer decisions, consumer purchasing, or driver behavior, and NHTSA cannot practically control any of them.\1382\ In addition, NHTSA does not have the statutory authority or practical ability to control the actual vehicle miles traveled (VMT) by drivers. As the extent of emissions is directly dependent on the operation of motor vehicles, changes in any emissions that would result from NHTSA's finalized

CAFE standards are not changes NHTSA can practically control or for which NHTSA has continuing program responsibility.

\1382\ See, e.g., Dep't of Transp. v. Pub. Citizen, 541 U.S. 752, 772-73 (2004); S. Coast Air Quality Mgmt. Dist. v. Fed. Energy Regulatory Comm'n, 621 F.3d 1085, 1101 (9th Cir. 2010).

Regarding legal precedent cited by commenters, as noted in the Supreme Court's reversal in Dept. of Transportation v. Public Citizen, 541 U.S. 752 (2004), a “but for” causal relationship is insufficient to establish practical control where an agency lacks the statutory authority to prevent a certain resource use or emissions increase. Contrary to the commenters' claims, NHTSA is not an environmental regulator, and the agency's direction under EPCA is to set maximum feasible vehicle fuel economy standards by balancing four statutory factors, none of which have an environmental protection basis.

NHTSA, by this rule, does not cause indirect emissions under the General Conformity Rule, and a general conformity determination is not required. 3. Endangered Species Act (ESA)

Under Section 7(a)(2) of the Endangered Species Act (ESA), Federal agencies must ensure that actions they authorize, fund, or carry out are “not likely to jeopardize the continued existence” of any federally listed threatened or endangered species (collectively, “listed species”) or result in the destruction or adverse modification of the designated critical habitat of these species.\1383\ If a Federal agency determines that an agency action may affect a listed species or designated critical habitat, it must initiate consultation with the appropriate service--the U.S. Fish and Wildlife Service (FWS) of the Department of the Interior (DOI) or the National Oceanic and Atmospheric Administration's National Marine Fisheries Service of the Department of Commerce (together, “the Services”), or both, depending on the species involved--in order to ensure that the action is not likely to jeopardize the species or destroy or adversely modify designated critical habitat.\1384\ Under this standard, the Federal agency taking action evaluates the possible effects of its action and determines whether to initiate consultation.\1385\

\1383\ 16 U.S.C. 1536(a)(2).

\1384\ See 50 CFR 402.14.

\1385\ See 50 CFR 402.14(a) (“Each Federal agency shall review its actions at the earliest possible time to determine whether any action may affect listed species or critical habitat.”).

The Services have previously provided legal and technical guidance about whether CO2 emissions associated with a specific proposed Federal action trigger ESA Section 7(a)(2) consultation. NHTSA analyzed the Services' history of actions, analysis, and guidance in Appendix G of the MY 2012-2016 CAFE standards EIS and incorporates that analysis by reference here.\1386\ In that appendix, NHTSA looked at the history of the Polar Bear Special Rule and several guidance memoranda provided by FWS and the U.S. Geological Survey. Ultimately, DOI concluded that a causal link could not be made between CO2 emissions associated with a proposed Federal action and specific effects on listed species; therefore, no Section 7(a)(2) consultation would be required.

\1386\ Available on NHTSA's Corporate Average Fuel Economy website at: NHTSA, Appendix G: Endangered Species Act Consideration, In Final Environmental Impact Statement for Corporate Average Fuel Economy Standards, Passenger Cars and Light Trucks, Model Years 2012-2016, NHTSA: Washington, DC (2010), available at: https://static.nhtsa.gov/nhtsa/downloads/CAFE/2012-2016%20Docs-PCLT/2012-2016%20Final%20Environmental%20Impact%20Statement/Appendix_G_Endangered_Species_Act_Consideration.pdf (accessed: June 11, 2026).

Subsequent to the publication of that appendix, a court vacated the Polar Bear Special Rule on NEPA grounds, though it upheld the ESA analysis as having a rational basis.\1387\ FWS then issued a revised Final Special Rule for the Polar Bear.\1388\ In that final rule, FWS provided for ESA Section 7, that the determination of whether consultation is triggered is narrow and focused on the discrete effect of the proposed agency action. FWS wrote that, “the consultation requirement is triggered only if there is a causal connection between the proposed action and a discernible effect to the species or critical habitat that is reasonably certain to occur. One must be able to `connect the dots' between an effect of proposed action and an impact to the species and there must be a reasonable certainty that the effect will occur.” \1389\ The statement in the revised Final Special Rule is consistent with the prior guidance published by FWS and remains valid.\1390\ If the consequence is not reasonably certain to occur, it is not an “effect of a proposed action” and does not trigger the consultation requirement.

\1387\ In re: Polar Bear Endangered Species Act Listing and section 4(D) Rule Litigation, 818 F.Supp.2d 214 (D.D.C. Oct. 17, 2011).

\1388\ 78 FR 11766 (Feb. 20, 2013).

\1389\ 78 FR 11784-11785 (Feb. 20, 2013).

\1390\ See DOI, Guidance on the Applicability of the Endangered Species Act Consultation Requirements to Proposed Actions Involving the Emissions of Greenhouse Gases, Solicitor's Opinion No. M-37017, DOI: Washington, DC (2008), available at: https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37017.pdf (accessed: June 11, 2026).

In the NPRM for this action, NHTSA stated that, pursuant to Section 7(a)(2) of the ESA, NHTSA considered the effects of the proposed CAFE standards and reviewed applicable ESA regulations, case law, and guidance to determine what, if any, impact there might be to listed species or designated critical habitat. NHTSA stated that, based on this assessment, the agency determined that the action of setting CAFE standards does not require consultation under Section 7(a)(2) of the ESA.

During the public comment period, NHTSA received comments from the NRDC and other organizations asserting that the agency violated the ESA by failing to consult under Section 7.\1391\ The commenters argued that the rule's projected increases in CO2 emissions (approximately one billion metric tons by 2050) and NOX emissions (between 55,000 and 170,000 tons) satisfy the “may affect” threshold. Specifically, commenters claimed that the increased CO2 emissions will accelerate Arctic Sea ice loss, harming the threatened polar bear, while increased NOX emissions will lead to nitrogen deposition that harms the threatened bay checkerspot butterfly by creating soil conditions for invasive grasses. Finally, the commenters alleged that NHTSA failed to conduct a proper effects determination, claiming there was no evidence of such an assessment in the record.

\1391\ NRDC et al., Docket No. NHTSA-2025-0491-5928, at 15.

NHTSA disagrees with the commenters' assertions that this rulemaking triggers Section 7 consultation. As established by FWS guidance, a consultation requirement is triggered only if there is a causal connection between the proposed action and a discernible effect on a species or critical habitat that is reasonably certain to occur. While commenters cite broad studies linking global greenhouse gases to sea ice loss and regional nitrogen deposition to habitat degradation, they fail to establish a discrete, reasonably certain causal link between the specific incremental emissions attributable to this CAFE rulemaking and a discernible impact on the polar bear, the bay checkerspot butterfly, or any other listed species. It does not appear possible to establish a causal connection between the marginal vehicle emissions shifts resulting from this specific action and those localized environmental harms. Furthermore, NHTSA's review of the applicable ESA regulations, historical guidance, and case law discussed above constitutes the agency's formal effects determination, which satisfies the

agency's obligations under 50 CFR 402.14(a).

Based on this assessment, NHTSA determined that the action of setting CAFE standards does not require consultation under Section 7(a)(2) of the ESA. NHTSA's determination remains unchanged from the proposal and concludes the agency's review of this action under Section 7 of the ESA. 4. Other Regulatory Analyses Discussed in the Final SEIS

NHTSA conducted qualitative reviews of the impacts of action alternatives on potentially affected resources, including those related to the statutory requirements and orders listed below, in the Draft SEIS, and determined that setting CAFE standards for passenger cars and light trucks is not the type of activity to have impacts on such resource categories. NHTSA's determination remains unchanged from the proposal:

National Historic Preservation Act (NHPA);

Fish and Wildlife Conservation Act (FWCA);

Coastal Zone Management Act (CZMA);

Floodplain Management (E.O. 11988 and DOT Order 5650.2);

Preservation of the Nation's Wetlands (E.O. 11990 and DOT Order 5660.1a);

Migratory Bird Treaty Act (MBTA), Bald and Golden Eagle Protection Act (BGEPA), E.O. 13186; and

Department of Transportation Act (Section 4(f)).

A commenter noted that NHTSA should consult with other agencies or outside experts about causal connections between this final rule and the resource categories covered under ESA and other statutes and orders listed above, such as endangered species, ecological damage, wildlife, and wetlands.\1392\ In light of this comment, NHTSA re-evaluated its obligations under the ESA and other statutes, regulations, case law, and guidance. Ultimately, NHTSA arrived at the same determination as in the NPRM, namely that, though there may be a general association between the actions undertaken in this final rule and environmental impacts, as described in this preamble and the Final SEIS, the setting of CAFE standards for passenger cars and light trucks is not the type of activity that has impacts on the resource categories identified by the commenter. Furthermore, NHTSA lacks sufficient authority under EPCA to regulate for these purposes. As such, NHTSA finds it unnecessary to conduct any additional analyses beyond those conducted for the NPRM and the Draft SEIS.

\1392\ Roselie Bright, Docket No. NHTSA-2025-0491-4891, at 4.

This final rule is subject to E.O. 13045 (62 FR 19885, Apr. 23, 1997). Pursuant to E.O. 13045, NHTSA must prepare an evaluation of the environmental health or safety effects of the planned action on children, and an explanation of why the planned action is preferable to other potentially effective and reasonably feasible alternatives considered by NHTSA. Further, this analysis may be included as part of any other required analysis.

While children are more vulnerable to adverse health effects related to mobile source emissions, environmental and health effects associated with criteria pollutant and toxic air pollutant emissions estimated from the final standards vary over time and across alternatives, and negative effects, when estimated, are extremely small. In addition, as discussed above, effects will vary based on how manufacturers respond to standards and how consumers choose to drive. This preamble and the Final SEIS discuss air quality, climate, and their related environmental and health effects. In addition, Section V of this preamble explains why NHTSA believes the finalized CAFE standards are preferable to other alternatives considered. Together, this preamble and Final SEIS satisfy NHTSA's responsibilities under E.O. 13045. 6. Executive Order 14154: “Unleashing American Energy”

E.O. 14154, “Unleashing American Energy” (90 FR 8353, Jan. 29, 2025), announced the administration's policy regarding energy resources, specifically to promote the production, distribution, and use of reliable domestic energy supplies, including oil, natural gas, and biofuels; to ensure that all regulatory requirements related to energy are “grounded in clearly applicable law”; and “to eliminate the `electric vehicle (EV) mandate' and promote true consumer choice” \1393\ by “removing regulatory barriers to motor vehicle access; by ensuring a level regulatory playing field for consumer choice in vehicles; by terminating, where appropriate, State emissions waivers that function to limit sales of gasoline-powered automobiles; and by considering the elimination of unfair subsidies and other ill-conceived government-imposed market distortions that favor EVs over other technologies and effectively mandate their purchase by individuals, private businesses, and government entities alike by rendering other types of vehicles unaffordable.” \1394\ E.O. 14154 also directs agencies to adhere only to relevant legislated requirements for environmental considerations and to eliminate any considerations beyond these requirements. Further, E.O. 14154 specifically directed the CEQ to propose rescinding its NEPA regulations found at 40 CFR 1500. CEQ rescinded its NEPA regulations in an interim final rule published on February 25, 2025, which was adopted as final on January 8, 2026.\1395\

\1393\ E.O. 14154, sec. 2.

\1394\ E.O. 14154, sec. 2(e).

\1395\ See Removal of National Environmental Policy Act Implementing Regulations, 90 FR 10610 (Feb. 25, 2025) (interim final rule); 91 FR 618 (Jan. 8, 2026) (final rule).

This final rule follows the direction of E.O. 14154 to ensure that all analysis related to energy is grounded in clearly applicable law and that only the relevant legislated requirements for environmental considerations and any considerations beyond these requirements are eliminated from the assessment of maximum feasible standards and the Final SEIS. 7. Executive Order 14173: “Ending Illegal Discrimination and Restoring Merit-Based Opportunity”

E.O. 14173, “Ending Illegal Discrimination and Restoring Merit- Based Opportunity” (90 FR 8633, Jan. 31, 2025), removed “diversity, equity, and inclusion” (DEI) and “diversity, equity, inclusion, and accessibility” (DEIA) principles from mandates, policies, programs, activities, guidance, regulations, and requirements. This Executive Order revoked E.O. 12898, “Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations” (59 FR 7629, Feb. 11, 1994), which directed Federal agencies to identify and address, as appropriate, “disproportionately high and adverse human health or environmental effects of its programs, policies, and activities on minority populations and low-income populations.” \1396\ The final rule is in compliance with E.O. 14173, and the Final SEIS analyzes the impacts on the quality of life of all Americans potentially affected by the final rule.

\1396\ E.O. 12898, sec. 1-101.

Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq., as amended), whenever an agency is required to publish an NPRM or final rule, it must prepare and make available for public comment a regulatory flexibility analysis that describes the effect of the rule on small entities (e.g., small businesses, small organizations, and small governmental jurisdictions). No regulatory flexibility analysis is required if the head of an agency certifies the rule will not have a significant economic impact on a substantial number of small entities and publishes with the rule a statement of the factual basis for certifying that a rule will not have a significant economic impact on a substantial number of small entities.

NHTSA has considered the impacts of this final rule under the Regulatory Flexibility Act, and the NHTSA Administrator certifies this final rule will not have a significant economic impact on a substantial number of small entities. NHTSA's statement providing the factual basis for this certification pursuant to 5 U.S.C. 605(b) follows.

Small businesses are defined based on the North American Industry Classification System (NAICS) code.\1397\ One of the criteria for determining size is the number of employees in the firm. For establishments primarily engaged in manufacturing or assembling automobiles, the firm must have less than 1,500 employees to be classified as a small business. This rulemaking would affect motor vehicle manufacturers. As shown in Table VII-1, NHTSA has identified nine small manufacturers that produce passenger cars, light trucks, and SUVs. NHTSA acknowledges that some very new manufacturers may potentially not be listed. However, those new manufacturers tend to have transportation products that are not part of the light-duty vehicle fleet and have yet to start production of relevant vehicles.\1398\

\1397\ Classified in NAICS under Subsector 336--Transportation Equipment Manufacturing for Automobile and Light Duty Motor Vehicle Manufacturing (336110). See U.S. Small Business Administration, Table of Size Standards, effective March 17, 2023, U.S. Small Business Administration: Washington, DC (2023), available at: https://www.sba.gov/document/support-table-size-standards (accessed: June 10, 2026).

\1398\ 5 U.S.C. 605(b).

[GRAPHIC] [TIFF OMITTED] TR30SE26.222

\1399\ Estimated number of employees as of Jan. 2026, source: linkedin.com, zoominfo.com, rocketreach.co, and datanyze.com.

\1400\ Rough estimate of LDV production for MY 2025.

NHTSA believes that the final rule would not have a significant economic impact on small vehicle manufacturers. The final rule is intended to reset the CAFE standards consistent with NHTSA's statutory authority. In addition, under 49 CFR part 525, passenger car manufacturers building less than 10,000 vehicles per year can petition NHTSA to have alternative standards apply to them. The listed manufacturers producing gasoline- and diesel-powered vehicles do not currently meet the standard and must already petition NHTSA for relief. This final rule to amend standards is not expected to have a meaningful impact on these manufacturers--they are still expected to be required to go through the same process and petition for relief, as the amended standards are expected to exceed the maximum feasibility of these small manufacturers. Accordingly, a regulatory flexibility analysis was not prepared.

E.O. 13132, “Federalism” (64 FR 43255, Aug. 10, 1999), requires Federal agencies to develop an accountable process to ensure “meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications.” E.O. 13132 defines the term “[p]olicies that have federalism implications” to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.” Under this order, agencies may not issue a regulation that has federalism implications, which imposes substantial direct compliance costs, unless the Federal Government provides the funds necessary to pay the direct compliance costs incurred by the State and local governments, or the agencies consult with State and local officials early in the process of developing the final rule.

NHTSA has determined that this final rule does not implicate E.O. 13132 because it neither imposes substantial direct compliance costs on State, local, or tribal governments, nor does it

preempt State law. NHTSA is not taking any action regarding preemption in this final rule and has determined that even though EPCA gives the agency express preemption authority, preemption is best executed through other actions. This rule's purpose is to finalize amended CAFE standards. Nothing in EPCA/EISA provides that NHTSA must make a determination or pronouncement on preemption in actions setting or amending CAFE standards. Thus, this final rule does not implicate the consultation procedures that E.O. 13132 imposes on agency regulations that would either preempt State law or impose substantial direct compliance costs on State, local, or tribal governments, as the only entities subject to this final rule are vehicle manufacturers.

Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA) requires Federal agencies to prepare a written assessment of the costs, benefits, and other effects of a proposed or final rule that includes a Federal mandate likely to result in the expenditure by State, local, or tribal governments, in the aggregate, or by the private sector, of more than $100 million in any 1 year (adjusted for inflation with base year of 1995). Adjusting this amount by the implicit GDP price deflator for 2024 results with $187 million (125.23/66.939=1.87).\1401\ Before promulgating a rule for which a written statement is needed, Section 205 of UMRA generally requires NHTSA to identify and consider a reasonable number of regulatory alternatives and adopt the least costly, most cost effective, or least burdensome alternative that achieves the objective of the rule. The provisions of Section 205 do not apply when they are inconsistent with applicable law. Moreover, Section 205 allows NHTSA to adopt an alternative other than the least costly, most cost effective, or least burdensome alternative if NHTSA publishes with the rule an explanation of why that alternative was not adopted.

\1401\ Bureau of Economic Analysis (BEA), National Income and Product Accounts, NIPA Table 1.1.9: Implicit Price Deflators for Gross Domestic Product (2025), available at: https://apps.bea.gov/iTable/?reqid=19&step=2&isuri=1&categories=survey (accessed: June 9, 2026).

This final rule will not result in the expenditure by State, local, or tribal governments, in the aggregate, of more than $187 million annually, but it will result in cost savings exceeding that amount for vehicle manufacturers and their suppliers. In developing this final rule, NHTSA considered a range of alternative fuel economy standards. As explained in detail in Section V of the preamble above, NHTSA concludes its selected alternatives are the maximum feasible alternatives that achieve the objectives of this final rule, as required by EPCA/EISA.

Section 12(d) of the National Technology Transfer and Advancement Act (NTTAA) requires NHTSA to evaluate and use existing voluntary consensus standards in its regulatory activities unless doing so would be inconsistent with applicable law (i.e., the statutory provisions regarding NHTSA's vehicle safety authority) or otherwise impractical.\1402\ Voluntary consensus standards are technical standards developed or adopted by voluntary consensus standards bodies. Technical standards are defined by the NTTAA as “performance-based or design-specific technical specification and related management systems practices.” They pertain to “products and processes, such as the size, strength, or technical performance of a product, process, or material.” \1403\ Examples of organizations generally regarded as voluntary consensus standards bodies include the American Society for Testing and Materials, International, the SAE, and the American National Standards Institute (ANSI). If NHTSA does not use available and potentially applicable voluntary consensus standards, it is required by the act to provide Congress, through OMB, an explanation of reasons for not using such standards.

\1402\ 15 U.S.C. 272.

\1403\ 142 Cong. Rec. S1081 (Feb. 7, 1996) (statement of Sen. Rockefeller).

NHTSA is incorporating by reference two SAE standards into this rule. NHTSA considered several options for evaluating a vehicle's tow rating for purposes of classification as a non-passenger automobile and has opted to use trailer weight rating (TWR) defined in accordance with SAE J2807 in the finalized provisions for the new LDWF pathway. SAE J2807 is an objective, industry-accepted, test-based methodology for evaluating towing capacity. In addition, many U.S. and Japanese auto manufacturers have well-

documented use of SAE J2807 for their tow ratings dating back to at least 2015. This is discussed in more detail in Section VI, above. In addition, NHTSA has long referenced SAE J1100 for purposes of the definition of passenger-carrying volume. NHTSA is finalizing a technical change to the definition of passenger-carrying volume to update the title of SAE Surface Vehicle Recommended Practice J1100, Motor Vehicle Dimensions. Though not proposed in the NPRM, this change is being finalized as a technical amendment that has no regulatory impact. NHTSA is also adding SAE J1100 NOV2009 to the list of materials incorporated by reference in Sec. 523.11. This is also discussed in more detail in Section VI, above.

Under regulations issued by the Office of the Federal Register (1 CFR 51.5), an agency, as part of a proposed rule that includes material incorporated by reference, must summarize material that is proposed to be incorporated by reference and discuss the ways the material is reasonably available to interested parties or how the agency worked to make materials available to interested parties. At the final rule stage, regulations require that the agency seek formal approval, summarize the material that it incorporates by reference in the preamble of the final rule, discuss the ways that the materials are reasonably available to interested parties, and provide other specific information to the Office of the Federal Register.

NHTSA is incorporating by reference two SAE standards into this rule. NHTSA incorporates by reference SAE J2807 Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating and Trailer Weight Rating, specifically the TWR definition used in that standard. SAE J2807 establishes minimum performance criteria at GCWR and calculation methodology to determine tow-vehicle TWR for passenger cars, multipurpose passenger vehicles, and trucks. NHTSA's regulations will use TWR for manufacturers to determine whether a vehicle qualifies as a non-passenger automobile for purposes of the CAFE program. NHTSA also incorporates by reference SAE J1100 Motor Vehicle Dimensions (NOV2009). SAE J1100 defines a set of measurements and standard procedures for motor vehicle dimensions. NHTSA specifies that this standard should be used for measurements related to the definition of passenger-carrying volume as specified in 49 CFR part 523.

All standards incorporated by reference in this rule are available for review at NHTSA's headquarters in Washington, DC, and for purchase from SAE. In addition, SAE's Reading Room provides public access to foreign-government authored content and the sections of SAE standards that have been incorporated by reference into the CFR, at https://www.sae.org/standards/sae-reading-room.

Under the procedures established by the Paperwork Reduction Act of 1995 (PRA) (44 U.S.C. 3501 et seq.), Federal agencies must obtain approval from OMB for each collection of information they conduct, sponsor, or require through regulations. A person is not required to respond to a collection of information by a Federal agency unless the collection displays a valid OMB control number. This final rule implements changes that relate to information collections that are subject to the PRA. Accordingly, NHTSA is forwarding an Information Collection Request (ICR) for a modification to NHTSA's existing information collection for CAFE Reporting to OMB for approval.

This final rule modifies NHTSA's previously approved ICR for its CAFE program (OMB control number 2127-0019). NHTSA sought comment on its intention to seek approval from OMB for this modification in the proposal and forwarded the ICR to OMB for approval. OMB deferred approval of this ICR and instructed NHTSA to resubmit the ICR with publication of the final rule. NHTSA is now resubmitting its request for revision of its existing CAFE information collection.

NHTSA's ICR describes the nature of the information collections for the CAFE program and their expected burden. As described in the NPRM, the ICR covers requirements for manufacturers to submit information on CAFE standards, exemptions, vehicles, technologies, and CAFE compliance test results. Manufacturers also provide information on any of the flexibilities and incentives they use during the model year to comply with CAFE standards. These reporting requirements are necessary to ensure compliance with its CAFE program.

In the NPRM, NHTSA proposed changes to the CAFE program's standardized reporting templates for manufacturers to submit information to NHTSA on their vehicle production and CAFE credits used to comply with the CAFE standards. In the ICR for the NPRM, NHTSA proposed modifications to the previously approved collection, including: (1) amending reporting elements related to vehicle classification on the pre-model year and mid-model year reports; (2) removing data elements related to AC and OC fuel consumption incentive values (FCIVs), in line with the AC and OC FCIV alternative pathways ending with MY 2026; (3) removing reporting requirements for credit trading in line with NHTSA's proposal to end credit trading with MY 2027, which includes credit trade contracts, credit allocation plans, credit transaction requests, and credit value reports; and (4) updating the pre-model year and mid-model year reporting templates to align with revised requirements. NHTSA is also removing reporting related to fuel consumption incentive values earned by full-size pickup trucks, which ended in MY 2024. As noted in the NPRM, these changes are expected to result in a decrease in burden to respondents. As a result of these changes, NHTSA estimated the total annual burden associated with the ICR would be 4,576 hours, a decrease of 285 hours from the previously approved collection which had an estimated burden of 4,861 hours.

While NHTSA did not receive any comments about its burden estimates, NHTSA did receive comments on the proposed changes to reporting requirements. NHTSA discusses these comments and the agency's response in the relevant sections above (See Section VI.B.4). After reviewing the comments, NHTSA is revising reporting requirements, as discussed in Section VI. Accordingly, the modifications to the ICR from NHTSA's previous approval are as follows: (1) amending reporting elements related to vehicle classification on the pre-model and mid- model reports as discussed in Section VI.B.4; (2) removing reporting requirements for credit trading in line with NHTSA ending the program for credits earned after MY 2027 (though credits earned through MY 2027 may be traded and used for up to five model years after they were used); (3) removing information collection requirements related to AC and OC FCIV petitions, which are set to end in MY 2026; and (4) updating the pre-model year and mid-model year reporting templates to

align with finalized changes. NHTSA is also removing reporting related to fuel consumption incentive values earned by full-size pickup trucks, which ended in MY 2024. NHTSA determined that no changes to the burden estimates included in the NPRM are warranted. Therefore, for the ICR NHTSA is forwarding to OMB for approval, NHTSA estimates that the total burden for the collection is 4,576 hours and $0. For additional information, see the supporting documentation for this ICR that is posted to the docket.\1405\

\1405\ Docket No. NHTSA-2025-0491.