Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act

Engine and vehicle manufacturers, trade associations for the manufacturers and suppliers, and other special interest groups commented specifically on the regulatory updates the EPA proposed for the HD engine and vehicle GHG programs. Many of these commenters raised a common concern that informed the approach we are finalizing for our HD engine and vehicle regulations: the HD industry's request to ensure no disruption to NHTSA's fuel efficiency program. Section VII.C.2 of this preamble summarizes comments related to that concern and describes the approach we are broadly applying to the regulations after considering those comments. We note that several commenters suggested more specific changes to regulatory sections we proposed to revise or remove, and some commenters identified additional regulatory sections we should consider revising or removing. In section VII.C.3 of this preamble, we summarize the comments related to specific regulatory text and changes we are finalizing after considering those comments. See the Response to Comments document for more detailed summaries of and responses to comments related to specific HD engine and vehicle GHG regulations.

Commenters responded to the EPA's request for comment on the relationship between the EPA's and NHTSA's regulations. As stated at proposal, NHTSA's medium- and heavy-duty fuel efficiency regulations in 49 CFR part 535 refer to several sections in the EPA's 40 CFR parts 1036 and 1037 that the EPA proposed to modify or remove. In the proposal, we also noted that NHTSA's reporting and recordkeeping regulation in 49 CFR 535.8(a)(6) directs manufacturers to submit information to the EPA, and 49 CFR 535.8(a)(6) also provides direction to manufacturers to send the information directly to NHTSA in instances where the EPA does not have an electronic pathway to receive the information.\216\ We requested comment on whether any of the EPA's GHG test procedure, certification, and compliance program regulations should be retained with a CFR notation explaining that they only apply to NHTSA's HD fuel efficiency program. Regarding reporting, we also requested comment on the time required to transition from manufacturers supplying

data to the EPA to supplying the data directly to NHTSA.

\216\ See 49 CFR 535.8(a)(6).

Engine and vehicle trade organizations, individual manufacturers, and other organizations that commented on this topic expressed concern about the proposal to remove the EPA's GHG regulations, indicating that it would disrupt near-term certification for engine and vehicle manufacturers who would continue to be subject to fuel consumption standards under the NHTSA's fuel efficiency program. These commenters suggested that the EPA retain some or all of its GHG regulations until NHTSA is able to revise 49 CFR part 535 to independently implement their fuel efficiency program. In general, we agree with commenters that manufacturers should continue to have access to the regulations needed for NHTSA to effectively implement their program. At this time, NHTSA has not finalized regulations to update their HD fuel efficiency program under 49 CFR part 535. Therefore, after considering comments, and consistent with our request for comment on whether any of these provisions should be retained to support NHTSA's HD fuel efficiency program, we are only removing as proposed the EPA GHG standards in 40 CFR 1036.108, 1037.105, and 1037.106 and other provisions in 40 CFR parts 1036 and 1037 that only apply for the EPA. Relatedly, as discussed in more detail in section VII.C.3.c of this preamble, we are retaining regulatory provisions so that manufacturers will continue to submit their data and information to the EPA until NHTSA has updated their regulations and is prepared to accept the manufacturers' data and information directly.

To ensure NHTSA's fuel efficiency program remains implementable in the near-term, we are retaining the EPA regulations in 40 CFR parts 1036 and 1037 that NHTSA references. The Response to Comments document for this final action describes specific changes we are finalizing to remove the EPA's GHG standards and retain the necessary provisions for NHTSA's fuel efficiency program. We note here that we have generally replaced references to “CO2 standards” with “fuel consumption standards” throughout 40 CFR parts 1036 and 1037. However, we have not removed all references to CO2 emissions throughout these parts. CO2 emissions remain the basis of many of the test procedures and compliance provisions used in NHTSA's fuel efficiency program. As such, we are retaining many of the requirements to measure and report CO2 emissions in 40 CFR parts 1036 and 1037 to support the NHTSA's fuel efficiency program. To avoid extensive revisions throughout the parts, we are also amending the 40 CFR 1036.801 and 1037.801 definitions of “we (us, our)” to mean the EPA for issues related to criteria pollutant standards and to include NHTSA for testing, compliance, and approvals related to fuel consumption standards.

Another commenter expressed a preference that the EPA also retain its current responsibility for certification, noting that the Environment and Climate Change Canada (ECCC) currently accepts EPA certification and labeling for their greenhouse gas program, which simplifies the certification process for manufacturers exporting their vehicles to Canada. We will not be continuing to provide EPA certifications for GHG emissions because we are removing the GHG emission standards in this final action.

While some manufacturers expressed support for the broad rescission of all of the EPA's GHG regulations, other industry commenters focused their comments specifically on the HD GHG Phase 3 program, noting that the Phase 3 standards are infeasible and that the rule was an “EV mandate” in violation of the major questions doctrine. More consistently, commenters from the HD industry noted their urgent need for regulatory certainty regarding the HD GHG Phase 3 standards that are currently set to apply for MY 2027. These commenters indicated that this final action is likely to be challenged, which could lead to the possibility that the final action would be stayed and the existing GHG regulations would remain in place, including the more stringent standards beginning in MY 2027. One approach suggested by commenters to provide near-term certainty was that the EPA rescind the Phase 3 program separate from the Endangerment Finding rescission and allow industry to continue to meet the MY 2024 standards that are currently in place under the HD GHG Phase 2 program. Another suggested approach was that the EPA add a severability clause to the final action to allow for canceling or revising the GHG standards as originally adopted for MY 2027 and later vehicles and engines even if the Endangerment Finding or the broader GHG emission standards are not rescinded. The EPA is removing all GHG emission standards as noted in this preamble because we lack authority to set these standards. Therefore, we are not putting in place alternative GHG emission standards and are not committing to alternative GHG emission standards in a separate action. As stated previously, companies are still able to continue producing HD vehicles that meet the now non-existent HD engine and vehicle requirements if they so choose. 3. Changes to the Heavy-Duty Engine and Vehicle GHG Regulations

The EPA's HD engine and vehicle emission regulations are contained in two standard-setting parts. 40 CFR part 1036 includes the engine- based emissions regulations for both criteria pollutant and GHG emissions.\217\ 40 CFR part 1037 includes the vehicle-based emission regulations for criteria pollutant exhaust emissions, evaporative and refueling emissions, and GHG emissions.

\217\ Note that HD engine manufacturers are subject to criteria pollutant standards in 40 CFR part 86, subpart A, through MY 2026. In a recent rulemaking (88 FR 4296, Jan. 24, 2023), the EPA migrated criteria pollutant regulations from 40 CFR part 86, subpart A, to 40 CFR part 1036 with new requirements that apply to MY 2027 and later HD engines. See 88 FR 4326.

In the following preamble subsections, we describe the removal and amendment of specific portions of each of these regulatory parts. This action removes the MY 2014 and later HD GHG emission standards promulgated in HD GHG Phase 1, Phase 2, and Phase 3, collectively. As noted in section VII.C.2 of this preamble, in general we are retaining many provisions for NHTSA's fuel efficiency program under 49 CFR part 535. If NHTSA updates their regulations, then the EPA would consider a separate rulemaking to remove the remaining provisions related to the NHTSA fuel efficiency program, including the EPA's data collection responsibilities. a. 40 CFR Part 1036--Emission Standards and Compliance Provisions for Heavy-Duty Engines

40 CFR part 1036 contains regulations related to the final action titled “Control of Emissions from New and In-Use Heavy-Duty Highway Engines.” 40 CFR part 1036 continues to include emission standards and compliance provisions for criteria pollutant emissions and evaporative and refueling emissions that remain unchanged, but we are removing emission standards and compliance provisions for GHG exhaust emissions (i.e., CO2, nitrous oxide (N2O), and methane (CH4) for HD engines) in this final action, consistent with our proposal. 40 CFR part 1036 is divided into nine subparts with three appendices. Subpart A defines the applicability of part 1036 and gives an overview of regulatory requirements. Subpart B describes the emission standards and other requirements that must be met to certify engines under

this part. Subpart C describes how to apply for a certificate of conformity for HD engines. Subpart D addresses testing of production engines and hybrid powertrains. Subpart E addresses in-use testing, while Subpart F describes how to test engines to demonstrate compliance with the emission standards. Subpart G describes requirements, prohibitions, and other provisions that apply to engine manufacturers, vehicle manufacturers, owners, operators, rebuilders, and all others. Subpart H describes how manufacturers can optionally generate, bank, trade, and use emission credits to certify HD engines. Subpart I includes definitions and other reference material. Appendix A includes a summary of previous emission standards. Appendix B includes the transient duty cycles. Appendix C includes engine fuel maps used in the certification of specific vehicles to meet the HD vehicle emission standards.

This preamble subsection includes an overview of the regulations related to the HD engine program we are removing or revising. In general, we are amending 40 CFR part 1036 to remove all GHG emission standards, references to such standards, and certain related provisions; however, most of 40 CFR part 1036 is retained as it is for the EPA's HD engine criteria pollutant emission program. As described in section VII.C.2 of this preamble, after considering comments, we are also retaining provisions to which NHTSA specifically refers in their fuel efficiency regulations of 49 CFR part 535. In this preamble subsection we describe the amendments we are finalizing for 40 CFR part 1036, which include revising or removing GHG-related provisions and clarifying when a provision is retained specifically for NHTSA's fuel efficiency program; some amendments are also needed to retain the efficacy of the EPA's criteria pollutant emission standards. Table 11 provides a summary of the regulations we are removing or amending in 40 CFR part 1036 or have retained specifically for NHTSA's fuel efficiency program. BILLING CODE 6560-50-P

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In 40 CFR part 1036, subpart A, we added clarification in a new 40 CFR 1036.1(e) noting that the test procedure and compliance elements that previously applied to GHG emission standards, now only apply to implement NHTSA's HD fuel efficiency standards in 49 CFR part 535. We are finalizing minor changes to 40 CFR 1036.5(a) to differentiate more clearly the certification requirements for MD vehicles from those for HD engines.

Within 40 CFR part 1036, subpart B, we are removing as proposed 40 CFR 1036.108, which included the GHG emission standards for CO2, N2O, and CH4. We are retaining for NHTSA 40 CFR 1036.115(b) and 1036.130(c), which refer to fuel maps. As proposed, we are removing, and reserving to otherwise retain the existing section numbering, several paragraphs from 40 CFR 1036.150 that described interim provisions that have equivalent provisions in 49 CFR part 535 or only applied for the EPA's GHG program, including: 40 CFR 1036.150(b), (e), (g)-(j), (l), (p), (w) and (aa). While we did propose to remove paragraphs (d), (m), (n), and (q)-(s), these interim provisions apply for NHTSA's program, and we are

retaining them with revisions to remove references to GHG emission standards.

We did not propose changes to the onboard diagnostic (OBD) regulations in 40 CFR part 1036, subpart B but we received comments that GHG-related requirements are embedded within California's 2022 OBD-II regulations that the EPA incorporates by reference. Commenters requested that the EPA exclude active technology, CO2 parameters, and reporting CO2 results during an OBD demonstration in the same manner as we previously excluded other specific California OBD requirements that did not apply for meeting the EPA regulations. Since we are removing GHG standards and related requirements in this final action, we agree that it is appropriate to also remove the requirement to monitor GHG parameters as part of OBD. For the final action, to conform with our removal of the EPA GHG standards, we are adding new paragraphs 40 CFR 1036.110(b)(14) through (18) to exclude the definition of “Active Technology” and related standardization, data storage, certification documentation, and monitoring system demonstration requirements from the EPA OBD provisions under 40 CFR 1036.101.

In 40 CFR part 1036, subpart C, we are retaining for NHTSA references to family emission limit (FEL) and family certification limit (FCL) that we proposed to remove, and are generally replacing references to CO2 FCLs or standards with more generalized text to apply for NHTSA. Also, for NHTSA, we are retaining with revisions 40 CFR 1036.230(f) and (g) that we proposed to remove. The revised 40 CFR 1036.230(f) and (g) now refer to 49 CFR part 535 and remove references to GHG standards in the description of how manufacturers divide their product lines into engine families. In 40 CFR 1036.230(f)(5) and throughout 40 CFR part 1036, we remove reference to EPA approvals related to GHG emissions. Therefore, under this final action, manufacturers would only need to obtain approval from NHTSA for elements related to their fuel efficiency program. We are also finalizing several revisions in 40 CFR 1036.235 to refer to 49 CFR part 535 and remove references to GHG emission testing requirements. In 40 CFR 1036.235(a), we are migrating text from 40 CFR 1037.235(a) that provides direction on how manufacturers select the test powertrain to replace GHG-related testing requirements in 40 CFR 1036.235(a)(4). We are retaining for NHTSA 40 CFR 1036.241 that we proposed to remove but are finalizing revisions to refer to 49 CFR part 535 and removing references to GHG standards in the description of how to demonstrate compliance.

Also in 40 CFR part 1036, subpart C, we are migrating as proposed the provisions that relate to powertrain families from the vehicle standard-setting part in 40 CFR 1037.231 to the engine standard-setting part as a new 40 CFR 1036.231 and are finalizing revisions described in this section VII.C.3.a of the preamble. In a previous rule (89 FR 29616, Apr. 22, 2024), we migrated the powertrain test procedure from the HD vehicle procedures (formerly 40 CFR 1037.550) to the HD engine procedures in 40 CFR 1036.545 because we expected powertrain testing to be primarily used by engine manufacturers. Similarly, we proposed to migrate the related provisions manufacturers would use to divide their product line into powertrain families by migrating the text from the vehicle program in 40 CFR 1037.231 to a newly created section in the engine program under 40 CFR 1036.231. We are finalizing that migration and modifying as proposed the text previously under 40 CFR 1037.231(b)(1), such that the new 40 CFR 1036.231(b)(1) no longer requires powertrains to share the same engine families described in 40 CFR 1036.230 but requires the engine share the same design aspects specified in 40 CFR 1036.230. Since a manufacturer may choose to certify the whole powertrain to the standards in 40 CFR part 1036, there would only be a powertrain family, not a certified engine family that contains just the engine. Similarly, and consistent with our approach for defining engine families in existing 40 CFR 1036.230, we see no need to limit the powertrain family based on the vehicle service class the powertrain goes into and therefore did not migrate the existing 40 CFR 1037.231(b)(2) that requires powertrain families to share vehicle service class groupings. We are also not migrating “energy capacity” as an example attribute in the new 40 CFR 1036.231(b)(10), since it is not needed for the criteria pollutant standards. Similarly, we are not migrating existing 40 CFR 1037.231(b)(11) since rated output of hybrid mechanical power technology is also not needed for a criteria pollutant family definition.

In 40 CFR part 1036, subpart D, we are retaining for NHTSA 40 CFR 1036.301 with revisions to refer to 49 CFR part 535 and remove references to CO2 in the description of the requirements for selective enforcement audits.

As previously noted, we retained and did not reopen the in-use testing procedures in 40 CFR part 1036, subpart E, which apply for the criteria pollutant emission standards. More specifically, within the in-use test procedures, we are retaining references to measuring CO2 for use in required chemical balance test procedures and to calculate the criteria pollutant emissions values for in-use testing. Also, in 40 CFR 1036.415(g), we are retaining the existing text requiring manufacturers to override any adjustable idle-reduction features on vehicles used for in-use testing; we are not taking action at this time on the proposed more general statement describing what it means to be adjustable.

In 40 CFR part 1036, subpart F, we are retaining for NHTSA test procedures related to developing engine data to support NHTSA's HD vehicle fuel efficiency program. We are retaining 40 CFR 1036.505, 1036.535, 1036.540, 1036.543, and 1036.550 and the fuel map duty cycle in Appendix C to part 1036 that we proposed to remove. In 40 CFR 1036.510, we are finalizing several revisions to paragraph (b), including replacing a reference to 40 CFR 1036.540(c)(2) with a reference to a new table we are including in that section as proposed that provides the same gear ratios based on engine service class from 40 CFR 1036.540. We are retaining 40 CFR 1036.510(e) and 1036.512(e), which described how to determine CO2 emissions for plug-in hybrid powertrains using the HD engine Federal Test Procedure (FTP) and engine Supplemental Emissions Test (SET) and duty cycles, respectively, to support NHTSA's HD fuel efficiency program. In 40 CFR 1036.530(e), we are retaining the existing requirement that manufacturers measure CO2 emissions for in-use testing, including the variable eCO2FTPFCL. We are not taking action at this time on the revised variable eCO2FTP that we proposed would represent the engine's brake-specific CO2 over the FTP or SET duty cycle.

Powertrain testing, also described in 40 CFR part 1036, subpart F, is an option that manufacturers may use for certifying hybrid powertrains to the engine criteria pollutant standards in 40 CFR 1036.104 and the GHG emission standards in 40 CFR 1036.108. The powertrain test procedure in 40 CFR 1036.545 describes testing a powertrain that includes an engine coupled with a transmission, drive axle, and hybrid components, or a subset of these components. We retained and did not reopen most of 40 CFR 1036.545 related to the powertrain testing for criteria pollutants. We proposed to remove the portions related to the GHG program and revise several paragraphs to account for the removed GHG content; however,

we are retaining these provisions for NHTSA's fuel efficiency program with targeted revisions to replace references to the EPA's standards with NHTSA's standards. While we are retaining vehicle test procedures from 40 CFR part 1037, we are finalizing as proposed the revisions in 40 CFR 1036.545(d) to replace references to the 40 CFR 1037.565 vehicle test procedure with the relevant text from that procedure.

Throughout 40 CFR 1036.545, we are retaining existing requirements to create inputs for the Greenhouse gas Emission Model (GEM) tool that manufacturers use for compliance with NHTSA's fuel efficiency program. Vehicle manufacturers will continue to have access to GEM Phase 2, Version 4.0, including the hardware-in-the-loop (HIL) model within that version of GEM, that is incorporated by reference in 40 CFR 1037.810 and currently available on the EPA's website.\218\ We also are retaining references to the use of utility factors, vehicle configurations, and vehicle-based duty cycles and test procedures that do not apply for the criteria pollutant program but apply to NHTSA's fuel efficiency program. We are removing as proposed 40 CFR 1036.545(p) which described the procedure to determine usable battery energy for plug-in hybrid powertrains that was added in the EPA's HD Phase 3 rule.

\218\ GEM Phase 2, Version 4.0 is incorporated by reference in 40 CFR 1036.545. See also 40 CFR 1036.810.

In 40 CFR part 1036, subpart G, we are revising 40 CFR 1036.605 to remove the EPA N2O requirements for engines installed in specialty vehicles and the ability to generate or use credits and are finalizing similar changes in 40 CFR 86.007-11(g) and 86.008-10(g) for MY 2026 and earlier specialty vehicle engines. We are retaining 40 CFR 1036.610 with a revised section heading to remove reference to GHG emissions, because NHTSA's regulations in 49 CFR part 535 refer to these off-cycle technology test procedures. We are also retaining for NHTSA 40 CFR 1036.615 and 1036.620, with revisions to 40 CFR 1036.620 to remove references to CO2 standards and banked credits, and the labeling requirement of paragraph (d). We are removing as proposed 40 CFR 1036.625, which described how to adjust CO2 FEL values; the NHTSA regulations contain their own provisions for manufacturers to make adjustments to their compliance values and they do not refer to 40 CFR 1036.625.

We also are removing as proposed 40 CFR 1036.635, which described how manufacturers that certify engines for use in high-gross combined vehicle weight (GCWR) MD vehicles under 40 CFR part 1036 could comply with GHG standards under 40 CFR part 86, subpart S. With no need to describe the GHG-related flexibilities in 40 CFR 1036.635, the existing applicability provisions in 40 CFR 1036.1 and 1036.5 already cover the certification provisions for high-GCWR vehicles as they relate to criteria pollutants. Specifically, 40 CFR 1036.1 sets up the default of applying the standards and certification requirements from 40 CFR part 1036 to all engines installed in HD vehicles (generally vehicles above 8,500 pounds GVWR), while 40 CFR 1036.5 allows manufacturers to certify MD vehicles to the chassis-based program as described in 40 CFR 86.1801-12.

The NHTSA regulations under 49 CFR part 535 contain their own ABT provisions for calculating and using fuel consumption credits. In 40 CFR part 1036, subpart H, we are generally removing references to the EPA's CO2 standards and are amending the calculation provisions to clarify they only apply for the EPA criteria pollutant credit calculations. We are retaining the ABT reporting provisions of 40 CFR 1036.730, since the EPA will continue to collect the information as described in 40 CFR 1036.755 for NHTSA's fuel efficiency program. The allowance for manufacturers to generate credit deficits under 40 CFR 1036.745 is required for NHTSA's ABT program for its fuel consumption standards. We are retaining for NHTSA 40 CFR 1036.745 and references to that section within subpart H, but are replacing the content of 40 CFR 1036.745 with a reference to NHTSA's fuel consumption credits provisions under 49 CFR 535.7.

In 40 CFR part 1036, subpart I, we proposed to remove GHG-specific symbols, abbreviations, and acronyms from 40 CFR 1036.805, and materials from 40 CFR 1036.810 that were only incorporated by reference in the test procedures we proposed to remove. Similarly, in 40 CFR 1036.801, we proposed to remove several GHG-specific definitions, and move transmission- and other powertrain-related definitions from the HD vehicle definitions in 40 CFR 1037.801 to the engine definitions in 40 CFR 1036.801, so they can be available to engine manufacturers using the powertrain test procedures in 40 CFR 1036.545. For the final action, we are retaining the provisions in 40 CFR 1036.801, 1036.805, 1036.810, and 1036.815 to provide for the implementation of NHTSA's fuel efficiency program. We are finalizing as proposed the new transmission- and other powertrain-related definitions in 40 CFR 1036.801 since the powertrain test procedures are now in 40 CFR part 1036, but note that we are also retaining the same definitions in 40 CFR 1037.801.

We proposed to remove Appendix C to part 1036, which contains the default engine fuel maps that are used by 40 CFR 1036.540. In this final action, we are retaining Appendix C, consistent with our decision to retain 40 CFR 1036.540 and the other provisions needed by NHTSA for their fuel efficiency program. b. 40 CFR Part 1037--Emission Standards and Compliance Provisions for Heavy-Duty Vehicles

40 CFR part 1037 contains regulations related to the final action titled “Control of Emissions from New Heavy-Duty Motor Vehicles.” 40 CFR part 1037 continues to include criteria pollutant emission standards that apply for all HD vehicles, and evaporative and refueling emission standards that apply for certain HD vehicles, but we are removing GHG emission standards, consistent with the proposal. 40 CFR part 1037 is divided into nine subparts with five appendices. Subpart A defines the applicability of part 1037 and gives an overview of regulatory requirements. Subpart B describes the emission standards and other requirements that must be met to certify vehicles under this part. Subpart C describes how to apply for a certificate of conformity. Subpart D and E address testing of production and in-use vehicles, respectively. Subpart F describes how to test vehicles and perform emission modeling for vehicles subject to the CO2 emission standards. Subpart G, along with 40 CFR part 1068, describe requirements, prohibitions, and other provisions that apply to manufacturers, owners, operators, rebuilders, and all others. Subpart H describes how manufacturers can optionally generate and use emission credits to certify vehicles. Subpart I includes definitions and other reference material. Finally, Appendix A, B, and D include test cycles, Appendix C presents emission control identifiers for emissions labels, and Appendix E presents power take-off utility factors.

This preamble subsection includes an overview of the regulations related to the HD vehicle program we are removing or revising. In general, we are amending 40 CFR part 1037 to remove all GHG emission standards (i.e., CO2 and HFC standards for vehicles), references to such standards, and certain related provisions without revising provisions necessary to support criteria pollutant standards, including

evaporative and refueling emission standards. As described in section VII.C.2 of this preamble, after considering comments, we are retaining provisions to which NHTSA specifically refers in their fuel efficiency regulations of 49 CFR part 535. In this preamble subsection, we describe the amendments to revise the GHG-related provisions from 40 CFR part 1037, which include some amendments needed to retain the efficacy of the criteria pollutant emission standards or clarify when a provision is retained specifically for NHTSA's fuel efficiency program. Table 12 provides a summary of the regulations we are removing or amending in 40 CFR part 1037 or have retained specifically for NHTSA's fuel efficiency program. BILLING CODE 6560-50-P [GRAPHIC] [TIFF OMITTED] TR18FE26.014

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In 40 CFR part 1037, subpart A, we retained and did not reopen the existing applicability of 40 CFR part 1037. Specifically, as described in existing 40 CFR 1037.1, the part continues to apply for BEVs, fuel cell electric vehicles (FCEVs), and vehicles fueled by conventional and alternative fuels. We added clarification in a new 40 CFR 1037.1(c) noting that the test procedure and compliance elements that previously applied to GHG emission standards, now only apply to implement NHTSA's HD fuel efficiency program in 49 CFR part 535. We note that the revised 40 CFR part 1037 continues to contain provisions that apply to HD vehicles under NHTSA's fuel efficiency program; however, it applies for fewer vehicles under the EPA's criteria pollutant program. Without EPA GHG standards, there are no vehicle-level emission standards for vehicles (including glider vehicles) with engines certified to other parts. Under this final action, the only HD vehicles that would continue to require a vehicle-level certificate of conformity from the EPA are those with no installed propulsion engine, such as BEVs and FCEVs, certifying to the criteria pollutant standards of 40 CFR 1037.102. Tailpipe emissions of criteria pollutants from BEVs and FCEVs would continue to be deemed to be zero with no testing

requirements, but the EPA will require that BEV and FCEV manufacturers apply for a certificate of conformity to meet the requirements of CAA section 202(a).

In 40 CFR part 1037, subpart B, we are removing the MY 2014 and later HD vehicle CO2 emission standards promulgated in HD GHG Phase 1, Phase 2, and Phase 3, which included the vocational vehicle standards in 40 CFR 1037.105 and the tractor standards in 40 CFR 1037.106. While we are removing GHG standards and related requirements, we retained and did not reopen criteria pollutant exhaust emission standards in 40 CFR 1037.102 and the evaporative and refueling emission standards in 40 CFR 1037.103.

We proposed to revise 40 CFR 1037.102(a) to describe how vehicles can be deemed to meet the criteria pollutant exhaust emission standards without testing under 40 CFR part 1037. Commenters raised concerns with the proposed approach to adopt new vehicle family definitions citing an associated need for new labeling, tracking systems, and reporting systems that would require additional time to implement. The commenters requested to keep today's vehicle family definitions, as they are required by NHTSA. After considering these comments, we note that the EPA did not intend for the new vehicle family definitions to increase burden on certifying manufacturers. Since vehicles with a propulsion engine are already covered under EPA engine certificates for criteria pollutants, we do not need to require a separate vehicle certificate for criteria pollutants. Therefore, we are retaining the current language in 40 CFR 1037.102(a) and (b) such that only vehicles without a propulsion engine will continue to be subject to the criteria pollutant standards in 40 CFR part 1037.

In the HD GHG Phase 2 rulemaking, we adopted PM emission standards that apply for APUs installed on new tractors. Since PM emissions are criteria pollutant emissions, we retained and did not reopen the PM emission standards for APUs but proposed to migrate the standards from 40 CFR 1037.106(g) to a new 40 CFR 1037.102(c) because we proposed to remove 40 CFR 1037.106. We are finalizing our proposed migration from 40 CFR 1037.106 and are modifying as proposed 40 CFR 1039.699(a) and (n) to refer to the new 40 CFR 1037.102 instead of 40 CFR 1037.106.

Also in 40 CFR part 1037, subpart B, we are amending 40 CFR 1037.115 to remove the HFC emission (i.e., air conditioning leakage) standards and the battery durability monitor requirements. We are revising as proposed the list of components covered under 40 CFR 1037.120(c). Under this final action, we are removing many HD vehicle GHG-reducing technologies but emission-related warranty would continue to apply for fuel cell stacks, RESS, and other components used with BEVs or FCEVs certified to the EPA's criteria pollutant standards or evaporative and refueling emission controls on vehicles subject to the EPA's evaporative and refueling standards. We are finalizing as proposed the removal of warranty requirements from 40 CFR part 1037 for RESS and other components used in hybrid vehicles. We note that manufacturers certifying hybrids to the EPA's criteria pollutant program would be doing so under the engine standards of part 1036 and would warrant the RESS and other components from those systems under 40 CFR part 1036. We did not reopen or propose to remove the warranty requirements for hybrid system components in 40 CFR part 1036.

We acknowledge commenters' suggestion that warranty should not apply for vehicles with no propulsion engine and no tailpipe emissions; however, these components are covered under the EPA's criteria pollutant program and the related warranty comments are out of scope for this action. We did not reopen the requirement that the basic emission-related warranty applies for fuel cell stacks and RESS as they continue to qualify as an emission-related component related to criteria pollutant emission standards. Therefore, we are retaining these provisions for the final action. Similarly, we retained and did not reopen the emission control components covering a vehicle's evaporative and refueling emissions.

Under this final action, we are finalizing a revision to replace the content of existing maintenance provisions of 40 CFR 1037.125 with a single sentence requiring manufacturers to provide written instructions for properly maintaining the emission control system.\219\ In the labeling provisions of 40 CFR 1037.135(c) we are removing as proposed paragraphs (c)(6) and (7) that relate to identifying the EPA- specific emission control system and fuel sulfur levels on the label, respectively. We proposed to remove 40 CFR 1037.140 and 1037.150, which included the vehicle classifications and interim provisions related directly to NHTSA's HD vehicle fuel efficiency program. In this final action, we are retaining 40 CFR 1037.140 with revisions to remove reference to the EPA's standards and we are retaining the NHTSA- referenced paragraphs of 40 CFR 1037.150 to assist in the continued implementation of NHTSA's program.

\219\ We are not aware of any scheduled maintenance for evaporative and refueling emission control components, or BEV or FCEV components, but if there was then the maintenance provisions of 40 CFR 1037.125 would apply.

In 40 CFR part 1037, subpart C, we proposed to remove 40 CFR 1037.201(g) that describes confirmatory testing; however, in this final action, we are retaining paragraph (g) for NHTSA's fuel efficiency program. We proposed to remove several provisions in 40 CFR 1037.205, which defines what manufacturers would include in their application for certification, because they would no longer be needed for GHG certification. However, in this final action we are instead revising 40 CFR 1037.205 to reflect the information that is required for NHTSA's fuel efficiency program.

We are retaining for NHTSA the existing 40 CFR 1037.225 and 1037.230 with minor revisions to remove reference to GHG and CO2 standards. After considering comments, we are not finalizing the streamlined vehicle families we proposed for 40 CFR 1037.230 to avoid additional burden for manufacturers certifying to NHTSA's fuel consumption standards using the original vehicle families. We are finalizing as proposed the migration of the powertrain families provision from 40 CFR 1037.231 to the HD engine regulations under a new 40 CFR 1036.231. We are retaining 40 CFR 1037.231 but replacing the content of that section with a reference to the new location of the provision in 40 CFR 1036.231. We proposed to remove 40 CFR 1037.232 and 1037.241 and revise 40 CFR 1037.235 and 1037.250, but are retaining them for NHTSA in this final action, with targeted revisions to remove references to GHG and CO2 standards.

We proposed to remove 40 CFR part 1037, subparts D and E in their entirety because they describe the testing of production and in-use vehicles to demonstrate compliance with the EPA's HD CO2 emission standards. However, we are retaining these provisions in this final action for NHTSA's fuel efficiency program. While the EPA would not be administering any production or in-use testing for GHG emissions, NHTSA references 40 CFR 1037.301 through 1037.320 which include audit procedures for inputs to the GEM, tractor aerodynamic testing, powertrain testing, and axle and transmission testing, and also references 40 CFR 1037.401 for in-use testing provisions.

We proposed to remove 40 CFR part 1037, subpart F, in its entirety because it included the testing and modeling provisions necessary to certify HD vehicles to the CO2 emission standards. The provisions in 40 CFR 1037.501 through 1037.570 include procedures for vehicle-based duty cycles for measuring CO2 emissions, aerodynamic testing, powertrain component testing, testing with hybrid power take-off units, and the use of GEM. We are retaining all of 40 CFR part 1037, subpart F because these test procedures are referred to by NHTSA in 49 CFR part 535. We are retaining the existing text for most sections of 40 CFR part 1037, subpart F, but we are finalizing some targeted revisions to 40 CFR 1037.501, 1037.520, 1037.540, 1037.551, and 1037.555 to replace references to CO2 standards with references to NHTSA's fuel consumptions standards. In 40 CFR 1037.560, 1037.565, and 1037.570, we are removing references to “critical emission-related maintenance” which only applies for the EPA. Since the NHTSA regulations currently refer to 40 CFR 1037.550, which the EPA removed in a previous rule when the powertrain test procedure was migrated to 40 CFR 1036.545 (89 FR 29616 April 22, 2024), we are restoring 40 CFR 1037.550 for NHTSA with a single sentence that directs readers to the correct 40 CFR 1036.545 for the powertrain test procedure.

We proposed to remove several sections of 40 CFR part 1037, subpart G, relating to special compliance provisions for the HD vehicle GHG emission standards. However, we are retaining all of the provisions required for the implementation of NHTSA's fuel efficiency program in 49 CFR part 535. These sections include provisions related to off-cycle technologies, advanced technologies, special purpose tractors, variable vehicle speed limiters, and idle reduction technologies. We are removing as proposed 1037.645, 1037.665, and 1037.670, which are not referenced by NHTSA.

We received a comment on 40 CFR 1037.605, in 40 CFR part 1037, subpart G, which allows manufacturers to use nonroad-certified engines in certain specialty highway vehicles. While we proposed to remove the vehicle labeling requirements in 40 CFR 1037.605(d), we did not propose any changes to paragraphs (a) through (c), which specify how the provisions apply for vehicle manufacturers using this allowance. The existing provisions apply for up to 200 all-terrain vehicles with specific axles, amphibious vehicles, and low speed vehicles. Through MY 2027, the provisions also apply for up to 1,000 vehicles with a hybrid powertrain where the engine provides energy only for the RESS. The commenter suggested that the EPA extend the hybrid provision beyond MY 2027 to allow the manufacturer to make a small number of hybrid fire trucks per year. The commenter cited compliance challenges associated with obtaining a highway-certified hybrid and that the existing hybrid sunset date was based on an expected increasing prevalence of HD hybrid powertrains, which is not occurring. As noted, we did not propose changes to the general provisions of 40 CFR 1037.605, and, therefore, this request is outside of the scope of this action. We may consider changes to this provision in a future rulemaking.

We proposed to remove 40 CFR part 1037, subpart H in its entirety. The provisions of 40 CFR 1037.701 through 1037.750 describe the averaging, banking, and trading of CO2 emission credits, along with associated recordkeeping and reporting requirements. We are retaining the regulatory provisions that are required by NHTSA for implementation of the fuel efficiency program. These include 40 CFR 1037.725, 1037.730, 1037.735, 1037.740, 1037.745, and 1037.755. We are removing as proposed 40 CFR 1037.705, 1037.710, 1037.715, 1037.720, and 1037.750. Throughout subpart H, we replace references to CO2 standards with references to NHTSA's fuel consumption standards, replace the term “emission credits” with a more generic “credits” term. Since the NHTSA regulations refer to 40 CFR 1037.745, we are retaining that section but are replacing the content with a sentence that points the reader to the equivalent credit deficit provision for NHTSA's fuel consumption credits under 49 CFR 535.7.

We proposed several revisions in 40 CFR part 1037, subpart I, to remove the GHG-specific definitions from 40 CFR 1037.801, and symbols, abbreviations, and acronyms from 40 CFR 1037.805. We also proposed to remove 40 CFR 1037.810, which includes materials incorporated by reference to support testing to demonstrate compliance with the HD vehicle GHG standards. This includes, but is not limited to, the GEM model and test procedures for measuring the rolling resistance of tires, tire revolutions per mile, and aerodynamics using coastdown, wind tunnel, and computational fluid dynamics. We are, however, retaining nearly all of subpart I in 40 CFR part 1037 because they are required to support NHTSA's 49 CFR part 535 regulations. We are removing the definition of “Phase 3” and revising the definitions of “Phase 1” and “Phase 2” to replace references to EPA standards with NHTSA's fuel consumption standards. As noted in section VII.C.2 of this preamble, we are also revising the definition of “we (us, our)” to include NHTSA for any regulations we are retaining related to fuel consumption standards. In Table 1 to paragraph (a) of 40 CFR 1037.805, we are removing the chemical species methane and nitrous oxide, which are GHG emissions used only by EPA regulations. In 40 CFR 1037.810, we are updating as needed references to regulatory sections or paragraphs that have been removed or changed in this final action.

Lastly, we proposed to remove all appendices to 40 CFR part 1037. Appendices A, B, and D include the test cycles related to HD vehicle GHG standards. Appendix C includes the emission control identifiers for GHG emission labels. Appendix E includes the power take-off unit utility factors applied in GHG-specific test procedures. We are retaining all of the existing appendices in 40 CFR part 1037 because they are required to support NHTSA's 49 CFR part 535 regulations. c. Relationship Between the EPA's GHG and NHTSA's Fuel Efficiency Medium- and Heavy-Duty Programs

The current certification and compliance process as relevant for NHTSA is as follows, separately for HD engines and HD vehicles:

1. Manufacturers submit fuel consumption data to the EPA using the EPA's electronic certification system following EPA test procedures included in 40 CFR parts 1036 and 1037;

2. The EPA issues certificates of conformity to the manufacturers;

3. Before and during the MY, the EPA sends the fuel consumption data and associated information to NHTSA;

4. After the MY, the EPA analyzes end-of-year reports submitted to the EPA by manufacturers for compliance and shares the fuel consumption data with NHTSA; and

5. NHTSA manages its compliance process related to the fuel consumption standards.

We proposed to remove 40 CFR 1036.755 and 1037.755, which describe the information the EPA provides to the Department of Transportation related to HD engine and vehicle fuel consumption. We noted that NHTSA's reporting and recordkeeping regulation in 49 CFR 535.8(a)(6) directs manufacturers to submit information to the EPA. 49 CFR 535.8(a)(6) also provides direction to manufacturers in instances where the EPA does not have an electronic pathway to receive the

information, to send it through an electronic portal identified by NHTSA, through the NHTSA CAFE database, or to send hardcopy documents to the address provided in the regulations. We requested comment on the time required to transition from manufacturers supplying data to the EPA to supplying the data directly to NHTSA.

Manufacturers and other commenters suggested that the EPA retain some or all of its GHG regulations until NHTSA is able to revise 49 CFR part 535 to independently implement their fuel efficiency program. After considering comments, we are removing as proposed the EPA GHG standards in 40 CFR 1036.108, 1037.105, and 1037.106 and other provisions in 40 CFR parts 1036 and 1037 that only apply for the EPA. However, to ensure NHTSA's fuel efficiency program remains implementable in the near-term, we are retaining the EPA regulations in 40 CFR parts 1036 and 1037 that NHTSA references, including the provisions where manufacturers submit data to the EPA.

Therefore, much of the current certification and compliance process outlined above will remain the same. At this time, the EPA intends to continue to maintain its Engines and Vehicles Compliance Information System (EV-CIS) and manufacturers will continue to have an EPA Designated Compliance Officer for submitting information regarding NHTSA's fuel efficiency program. However, we note that the EPA would not grant approvals related to special compliance provisions, issue EPA certificates of conformity for GHG emissions, or analyze end of year reports for compliance with the GHG emission standards. Furthermore, the EPA will perform confirmatory testing, in-use testing, or selective enforcement audits only in relation to the EPA criteria pollutant program. We note that vehicle manufacturers will continue to have access to the GEM Phase 2, Version 4.0 that is incorporated by reference in 40 CFR 1037.810 and currently available on the EPA's website. If NHTSA updates their regulations and is prepared to accept the manufacturers' data and information directly, then the EPA would consider a separate rulemaking to remove the remaining provisions related to the NHTSA fuel efficiency program, including the EPA's data collection responsibilities.

This is an economically significant regulatory action that was submitted to OMB for review. Any changes made have been documented in the docket. The EPA has prepared an RIA for this action to project impacts as required by E.O. 12866, and it can be found in the docket.\220\

\220\ “Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act: Regulatory Impact Analysis.” EPA-420-R-26-002. February 2026.

As we stated in the proposal, the EPA has not relied upon any aspect of the draft RIA or this final RIA as justification for this rulemaking. Some commenters suggested that the benefit-cost assessments provided in the draft RIA do not justify repealing the prior standards. However, the EPA is repealing the GHG emission standards for LD vehicles, MD vehicles, HD vehicles, and HD engines consistent with the discussion of legal authority in this preamble, and the EPA is not relying upon the CAA section 202(a) factors for standard-setting in this final action. For this final action, we have conducted benefit- cost assessments pursuant to E.O. 12866, but we recognize that there are costs and benefits that we are currently unable to fully quantify and monetize.

Commenters also stated that the EPA should have included an assessment of air quality and climate impacts from removing the motor vehicle and engine GHG standards. For this final action, the EPA performed modeling to estimate changes in criteria pollutants, air toxics, and GHG emissions. The projected emissions changes can be found in a memorandum in the docket for this action.\221\ The EPA also performed climate impacts modeling for this final action, which is documented in a memorandum in the docket for this action.\222\

\221\ See Memorandum to Docket EPA-HQ-OAR-2025-0194. “Projected Criteria, Air Toxics, and GHG Emissions Impacts for the “Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act” Final Rule.”

\222\ See Memorandum to Docket EPA-HQ-OAR-2025-0194. “Temperature, CO2 Concentration, and Sea Level Rise Impacts of Greenhouse Gas Emissions from U.S. Motor Vehicles.”

The analyses provided in the RIA have been revised since the rule was proposed to reflect a number of considerations, including some elements highlighted by commenters. The analyses rely on updated versions of the models used to analyze the impacts of the proposal, which were based on the models and tools used to estimate impacts of the light- and medium-duty, and the heavy-duty rules finalized by the EPA in 2024.\223\ A number of the updates made to the analysis, including in response to comments, are discussed below. For more information on updates to the analyses, see the RIA. For more information on the comments we received on the analysis in the proposal, as well as our responses, see the Response to Comments document. In addition to the changes noted in the following paragraphs, we updated the costs and benefits from 2022 dollars to 2024 dollars.

\223\ See “Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles: Regulatory Impact Analysis”, EPA-420-R-24-004, March 2024; and “Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles: Phase 3: Regulatory Impact Analysis, EPA-420-R-24-06, March 2024.

We received comments that the approach used in the EPA's OMEGA modeling of GHG standards for the proposed rule did not appropriately capture removing all GHG standards for LD and MD vehicles. Commenters stated that instead of extending the MY 2026 GHG standards into MYs 2027 and beyond, a more appropriate modeling approach would be to model no GHG standards at all, and to allow the OMEGA model to apply less emissions control technology to vehicles in each MY than in the prior MY (backsliding). For the analysis of this final action, we revised the OMEGA modeling assumptions to simulate the removal of all GHG standards for LD and MD vehicles, and revised the OMEGA model's run settings to allow backsliding.

Some commenters raised concerns that the 2024 GHG Emission Standards Rules relied on IRA tax credits and noted that Congress subsequently eliminated or modified these tax credits in the OBBB. We agree that our modeling should reflect the actions signed into law in the OBBB. For the proposal, our modeling assumed all pertinent tax credits were removed. For this final analysis, we revised our analyses to align with the OBBB by removing the credits for purchasing (26 U.S.C. 30D) and leasing (26 U.S.C. 45W) LD and MD BEVs; removing the vehicle purchase tax credits (26 U.S.C. 45W) for HD BEVs and HD FCEVs; removing the tax credit for electric vehicle supply equipment (EVSE) installation (26 U.S.C. 30C) for HD BEVs; and adjusting the phase-out of the advanced manufacturing production credit (26 U.S.C. 45X).

We received comments suggesting that the Agency's baseline assumptions for future HD EV market penetration were inflated due to California's Advanced Clean Truck (ACT) regulation. Congress disapproved the EPA's waiver for the ACT rule under the CRA. We agree with the commenters that our modeling should reflect Congress' decision regarding the EPA waiver for the ACT regulation and therefore we have completely removed California's ACT regulation from the modeling for the final action analysis.

We received conflicting comments related to consumer interest in EVs. Some stated that EV market share is and will be lower in the future than the EPA estimated in the 2024 GHG Emission Standards Rules and in the proposal. The main reasons cited by commenters were the passage of the OBBB and subsequent removal of IRA purchase and leasing tax credits leading to higher cost for consumers, the CRA resolution nullifying California's CAA preemption waiver for the Advanced Clean Cars (ACC) II regulation leading to decreased demand, and slower charging infrastructure development than estimated in the 2024 GHG Emission Standards Rules. On the other hand, some commenters stated that consumer demand for EVs is strong and growing, that states continue to provide incentives for EV purchases, and that there are continued strong investments in EV charging networks. After consideration of the comments, our assessment is that there is a reduced consumer interest in purchasing EVs overall. Therefore, we lowered the BEV acceptance parameter values in our modeling of this final action from those presented in the proposal.

Some commenters criticized the EPA's analysis in the DRIA for including a scenario that they characterized as using arbitrarily low fuel prices, citing the scenario with gasoline prices set at $1 and $0.25 per gallon less than the Energy Information Administration's (EIA) Annual Energy Outlook (AEO) 2023 Reference case for gasoline and diesel, respectively. Commenters stated that EIA's AEO 2025 projections included an Alternative Transportation case that reflects many of the changes that are occurring in the transportation sector, including the removal of California's ACT, the EPA's 2024 GHG Emission Standards Rules, and NHTSA's 2024 final rule for CAFE standards for MYs 2027- 2032, as well as assuming a slower growth for IRA credit eligibility than assumed in the AEO 2025 Reference case. We agree that the Alternative Transportation case energy prices are appropriate to use in our modeling for the case where the standards are removed, and we included it in our modeling for the final action. We also have revised the low gasoline and diesel price scenario; instead of using a $1 or $0.25 per gallon across-the-board decrease, we use prices from the Low Oil Price case presented in AEO 2025. In summary, the modeling we conducted for the final action includes future gasoline, diesel, electricity, and hydrogen prices that reflect EIA's AEO 2025 projections of the Reference, Alternative Transportation, and Low Oil Price cases.

In the RIA, the EPA presents results from four scenarios using the same analytical methods the EPA used in the 2024 GHG Emission Standards Rules that project the costs and benefits from removing the GHG standards for LD, MD and HD vehicles and HD engines. The results of these scenarios are summarized in Table 13 and Table 14. Except as noted this section VIII.A, and as discussed in the RIA, the models, assumptions and inputs are the same as those used in the 2024 RIAs.

The first scenario (A1) includes the revisions noted above, including the use of AEO 2025 Reference case fuel prices for the modeling of the no action case where the GHG standards remain in place, and the AEO 2025 Alternative Transportation fuel prices for modeling the action case where the GHG standards are removed. Recognizing the uncertainties related to projecting future gasoline and diesel prices, the second scenario (A2) considers the impacts under lower fuel prices, and uses AEO 2025's Low Oil Price case.

In the NPRM, the EPA presented two scenarios accounting for only the first two and a half years of fuel savings in estimating the net monetized impact of removing the GHG emission standards. Commenters suggested the Agency's adjustment was arbitrary and unsupported. Some commenters stated that the savings that accrue after the first two and a half years are a real-world benefit to consumers and society and therefore should be included in the benefit-cost assessment. Other commenters stated that the EPA should account for more than the first two and a half years of fuel savings but should not account for the full lifetime of fuel savings. The Agency also received comments that the approach of only including the first two and a half years of fuel savings was specifically not appropriate to apply to HD vehicles because they are for-profit businesses that account for fuel and maintenance savings when making purchasing decisions. For the final action, we continue to present results representing both a full lifetime of fuel savings (scenarios A1 and A2) and only the first two and a half years of fuel savings. The third (A3) and fourth (A4) scenarios build on the first and second scenarios respectively, accounting for only the first two and a half years of fuel savings in estimating the net monetized impacts of this action. The EPA believes the presented results provide reasonable bounds for the impact of fuel savings on the net monetized impacts of this action. Table 13 and Table 14 show the net present value of the monetized savings, costs, and net savings of the four scenarios presented at 7 and 3 percent discount rates, respectively.

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In Tables 15 and 16 we provide the estimated cost savings per vehicle at a seven percent net present value and a three percent net present value. As shown in the tables, the EPA's modeling projects this rule to result in about 469 million new combined LD, MD, and HD vehicle sales over the 2027 to 2055 time period under Scenarios A1 and A3, and about 472 million new combined LD, MD, and HD vehicle sales under Scenarios A2 and A4. With the estimated $730 billion reduction in vehicle technology cost at a seven percent discount rate, we estimate this action will result in an average cost reduction of $1,550 per vehicle under Scenarios A1 and A3. Under Scenarios A2 and A4 at a seven percent discount rate, the reduction in vehicle technology cost of about $750 billion are estimated to result in an average cost reduction of $1,600 per vehicle. With the estimated $1.09 trillion reduction in vehicle technology cost at a three percent discount rate for Scenarios A1 and A3, we estimate this action will result in an average cost reduction of $2,330 per vehicle. Under Scenarios A2 and A4 at a seven percent discount rate, the reduction in vehicle technology cost of about $1.14 trillion at a three percent discount rate are estimated to result in an average cost reduction of $2,420 per vehicle.

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Table 17 provides the GHG emission impacts in calendar year (CY) 2055 by emission source due to this action. For motor vehicles, total GHG emissions increase by 410 million metric tons (MMT) in carbon dioxide equivalent (CO2e). Table 18 provides the cumulative GHG emissions impact from CY 2027 through CY 2055. The total GHG emissions are estimated to increase by 8,300 MMT CO2e. [GRAPHIC] [TIFF OMITTED] TR18FE26.019

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The EPA discussed air pollutants not being directly impacted by this rule (i.e., criteria pollutants and hazardous air pollutants) within other documents within the docket. The EPA is obligated to ensure the public is not misled regarding the level of scientific understanding and the implications of that science when developing policies and regulations. Historically, however, the EPA's analytical practices often provided the public with false precision and confidence regarding the monetized impacts of fine particulate matter (PM2.5) and ozone than the underlying science could fully support, especially as overall emissions have significantly decreased and impacts have become more uncertain. The EPA's use of benefit per ton (BPT) monetized values introduces additional uncertainty. Although intended as a screening tool when full-form photochemical modeling was not feasible, the BPT approach reduces complex spatial and atmospheric relationships into an average value per ton, which magnifies uncertainty in the resulting monetized estimates. Examples of uncertainties include but are not limited to epidemiological uncertainty (e.g., concentration-response functions); economic factors (e.g., discount rates, income growth, willingness-to-pay to avoid mortality risk); and methodological assumptions (e.g., health thresholds, linear relationships, spatial relationships).

Despite these uncertainties, the EPA historically provided point estimates instead of just ranges or only quantifying emissions, which leads the public to believe the Agency has a better understanding of the monetized impacts of exposure to PM2.5 and ozone than it does in reality. Therefore, to rectify this error, the EPA is no longer monetizing benefits from PM2.5 and ozone but will continue to quantify the emissions until the Agency is confident enough in the modeling to properly monetize those impacts.

The information collection activities in this action have been submitted for approval OMB under the PRA. The Information Collection Requests (ICR) that the EPA prepared have been assigned numbers as indicated below. You can find a copy of the Supporting Statements in the docket for this action, and they are briefly summarized here.

An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB control number. The OMB control numbers for the EPA's regulations in Title 40 of the CFR are listed in 40 CFR part 9. When OMB approves this ICR, the Agency will announce that approval in the Federal Register and publish a technical amendment to 40 CFR part 9 to display the OMB control number for the approved information collection activities contained in this final action. 1. 2024 LD and MD Multi-Pollutant Emission Standards Rule

The ICR document prepared by the EPA for removal of the light- and medium-duty vehicle GHG requirements has been assigned EPA ICR 2750.03, revising EPA ICR 2750.02 (OMB 2060-0764). You can find a copy of the ICR in the docket for this action and it is briefly summarized here. The information collection requirements are not enforceable until OMB approves them.

The EPA is removing all regulations that require light- and medium- duty vehicle manufacturers to measure, report, or comply with standards for GHG emissions. Information collected to assure compliance with those requirements is no longer needed under this final action. All other requirements covered by 2750.02 remain in effect.

Respondents/affected entities: Light- and medium-duty vehicle manufacturers, alternative fuel converters, and independent commercial importers.

Respondent's obligation to respond: This action relieves manufacturers of the burden to provide certain information to the EPA as part of their annual MY vehicle certification under CAA section 208(a), which is required prior to entering vehicles into commerce. Participation in some programs is voluntary; but once a manufacturer has elected to participate, it must submit the required information.

Estimated number of respondents: 35 affected entities.

Frequency of response: Annually or on occasion, depending on the type of response.

Revised total estimated burden: 138,443 hours (per year) for remaining regulatory requirements covered by this ICR. Burden is defined at 5 CFR 1320.3(b).

Revised total estimated cost: $26.3 million per year for remaining regulatory requirements covered by this ICR, which includes an estimated $14.2 million annualized capital or operation and maintenance costs. 2. 2024 HD GHG Emission Standards Rule

The ICR document prepared by the EPA for removal of the 2024 HD GHG Emission Standards Rule requirements has been assigned EPA ICR 2734.03, revising EPA ICR 2734.02 (OMB 2060-0753). You can find a copy of the ICR in the docket for this action and it is briefly summarized here. The information collection requirements are

not enforceable until OMB approves them.

The EPA is removing all regulations that require HD motor vehicle and HD motor vehicle engine manufacturers to measure, report, or comply with the 2024 HD GHG Emission Standards Rule standards. Information collected to assure compliance with those requirements is no longer needed under this final action.

Respondents/affected entities: Manufacturers of HD onroad vehicles.

Respondent's obligation to respond: This action relieves manufacturers of the burden to provide certain information to the EPA as part of their annual MY engine and vehicle certification under CAA section 203(a), which is required prior to entering vehicles into commerce.

Estimated number of respondents: 77 affected entities.

Frequency of response: Originally expected to be one-time burden; now, no requirement to report.

Revised total estimated burden: 0 hours. Burden is defined at 5 CFR 1320.03(b).

Revised total estimated cost: $0. 3. Nonroad Compression-Ignition Engines and On-Highway Heavy-Duty Engines, Supporting Statement for Information Collection Request (March 2023 Revision)

We are not acting on the proposed changes to this ICR document to ensure this ICR will continue to cover the information collection necessary to implement NHTSA's MD and HD fuel efficiency program. The proposed changes to the ICR document can be found at EPA ICR 1684.22, revising EPA ICR 1684.21 (OMB 2060-0287).

The EPA is not acting on these revisions as they are no longer needed. As explained elsewhere in this preamble, in this final action we are not changing elements of the regulations that are necessary for programs unrelated to the GHG emission standards, including emission standards for criteria pollutants. We also are retaining most of the regulatory provisions cited by NHTSA for the administration of their fuel efficiency standards included in 49 CFR part 535. This includes the provisions that require manufacturers to submit their compliance data and information to the EPA and we will then issue a report to NHTSA with the information. However, we note that the EPA would no longer issue EPA certificates of conformity for GHG emissions.

I certify that this action will not have a significant economic impact on a substantial number of small entities under the RFA. In making this determination, the EPA concludes that the impact of concern for this action is any significant adverse economic impact on small entities, and that the Agency is certifying that this action will not have a significant economic impact on a substantial number of small entities because the action relieves regulatory burden on the small entities subject to the action.

The regulated entities that are subject to the regulations we are removing in this action are engine and vehicle manufacturers, alternative fuel converters, and independent commercial importers subject to GHG emission standards for vehicles. The Agency is certifying that this action will not have a significant economic impact on a substantial number of small entities because the action will relieve regulatory burden on all entities, including all small entities, subject to the current rules. This action removes portions of the regulations of the standard-setting parts directly related to GHG emission standards and compliance provisions for implementing the EPA's GHG engine and vehicle programs. We do not anticipate that there will be any significant adverse economic impact on directly regulated small entities as a result of these revisions. We have therefore concluded that this action will relieve regulatory burden for all directly regulated small entities. The EPA provides additional information on the RFA in chapter 7 of the RIA and in the Response to Comments for this final action.

E.O. 13045 directs Federal agencies to include an evaluation of the health and safety effects of the planned regulation on children in Federal health and safety standards and explain why the regulation is preferable to potentially effective and reasonably feasible alternatives. This action is subject to the E.O. because it is an economically significant regulatory action under E.O. 12866, and the EPA believes the environmental health or safety risks may have a disproportionate effect on children, although as explained in the preamble eliminating all GHG emissions from all vehicles would have a de minimis impact on public health or welfare. The 2021 Policy on Children's Health also applies to this action.\225\

\225\ U.S. Environmental Protection Agency. (2021). 2021 Policy on Children's Health: https://www.epa.gov/system/files/documents/2021-10/2021-policy-on-childrens-health.pdf.

Although the GHG emissions at issue in this rulemaking do not have direct impacts on human health, we acknowledge the possibility that this action could impact emissions of criteria pollutants and air toxics. Children are not expected to experience greater ambient concentrations of air pollutants than the general population. Additionally, as discussed in the preamble, there are safety benefits from this final action that would benefit children as they are more susceptible to grievous injuries from less safe motor vehicles.

We note that, as explained above, this action would not impact separate emission standards for criteria pollutants by the EPA or separate standards set by NHTSA. At this time, the EPA does not believe that the action would have a material adverse impact on the health of individuals with respect to non-GHG air pollutants, including on children, because the EPA anticipates that the impacts of repealing GHG emission regulations would have only marginal and incidental impacts on the emission of non-GHG air pollutants. Potential health impacts of such air pollutants will continue to be controlled through direct emissions limits and several other programs that target regional and national air quality, including the NAAQS program.