Link to an amendment published at 89 FR 29740, Apr. 22, 2024.

The provisions in this section apply instead of other provisions in this part. This section describes when these interim provisions expire, if applicable.

(a) Transitional ABT credits for NOX emissions. You may generate NOX credits from model year 2026 and earlier engines and use those as transitional credits for model year 2027 and later engines using any of the following methods:

(1) Discounted credits. Generate discounted credits by certifying any model year 2022 through 2026 engine family to meet all the requirements that apply under 40 CFR part 86, subpart A. Calculate discounted credits for certifying engines in model years 2027 through 2029 as described in § 1036.705 relative to a NOX emission standard of 200 mg/hp·hr and multiply the result by 0.6. You may not use discounted credits for certifying model year 2030 and later engines.

(2) Partial credits. Generate partial credits by certifying any model year 2024 through 2026 compression-ignition engine family as described in this paragraph (a)(2). You may not use partial credits for certifying model year 2033 and later engines. Certify engines for partial credits to meet all the requirements that apply under 40 CFR part 86, subpart A, with the following adjustments:

(i) Calculate credits as described in § 1036.705 relative to a NOX emission standard of 200 mg/hp·hr using the appropriate useful life mileage from 40 CFR 86.004-2. Your declared NOX family emission limit applies for the FTP and SET duty cycles.

(ii) Engines must meet a NOX standard when tested over the Low Load Cycle as described in § 1036.514. Engines must also meet an off-cycle NOX standard as specified in § 1036.104(a)(3). Calculate the NOX family emission limits for the Low Load Cycle and for off-cycle testing as described in § 1036.104(c)(3) with StdFTPNOx set to 35 mg/hp·hr and Std[cycle]NOx set to the values specified in § 1036.104(a)(2) or (3), respectively. No standard applies for HC, PM, and CO emissions for the Low Load Cycle or for off-cycle testing, but you must record measured values for those pollutants and include those measured values where you report NOX emission results.

(iii) For engines selected for in-use testing, we may specify that you perform testing as described in 40 CFR part 86, subpart T, or as described in subpart E of this part.

(iv) Add the statement “Partial credit” to the emission control information label.

(3) Full credits. Generate full credits by certifying any model year 2024 through 2026 engine family to meet all the requirements that apply under this part. Calculate credits as described in § 1036.705 relative to a NOX emission standard of 200 mg/hp·hr. You may not use full credits for certifying model year 2033 and later engines.

(4) 2026 service class pull-ahead credits. Generate credits from diesel-fueled engines under this paragraph (a)(4) by certifying all your model year 2026 diesel-fueled Heavy HDE to meet all the requirements that apply under this part, with a NOX family emission limit for FTP testing at or below 50 mg/hp·hr. Calculate credits as described in § 1036.705 relative to a NOX emission standard of 200 mg/hp·hr. You may use credits generated under this paragraph (a)(4) through model year 2034, but not for later model years. Credits generated by Heavy HDE may be used for certifying Medium HDE after applying a 10 percent discount (multiply credits by 0.9). Engine families using credits generated under this paragraph (a)(4) are subject to a NOX FEL cap of 50 mg/hp·hr for FTP testing.

(b) Model year 2014 N2O standards. In model year 2014 and earlier, manufacturers may show compliance with the N2O standards using an engineering analysis. This allowance also applies for later families certified using carryover CO2 data from model 2014 consistent with § 1036.235(d).

(c) Engine cycle classification. Through model year 2020, engines meeting the definition of spark-ignition, but regulated as compression-ignition engines under § 1036.140, must be certified to the requirements applicable to compression-ignition engines under this part. Such engines are deemed to be compression-ignition engines for purposes of this part. Similarly, through model year 2020, engines meeting the definition of compression-ignition, but regulated as Otto-cycle under 40 CFR part 86 must be certified to the requirements applicable to spark-ignition engines under this part. Such engines are deemed to be spark-ignition engines for purposes of this part. See § 1036.140 for provisions that apply for model year 2021 and later.

(d) Small manufacturers. The greenhouse gas standards of this part apply on a delayed schedule for manufacturers meeting the small business criteria specified in 13 CFR 121.201. Apply the small business criteria for NAICS code 336310 for engine manufacturers with respect to gasoline-fueled engines and 333618 for engine manufacturers with respect to other engines; the employee limits apply to the total number employees together for affiliated companies. Qualifying small manufacturers are not subject to the greenhouse gas emission standards in § 1036.108 for engines with a date of manufacture on or after November 14, 2011 but before January 1, 2022. In addition, qualifying small manufacturers producing engines that run on any fuel other than gasoline, E85, or diesel fuel may delay complying with every later greenhouse gas standard under this part by one model year. Small manufacturers may certify their engines and generate emission credits under this part before standards start to apply, but only if they certify their entire U.S.-directed production volume within that averaging set for that model year. Note that engines not yet subject to standards must nevertheless supply fuel maps to vehicle manufacturers as described in paragraph (n) of this section. Note also that engines produced by small manufacturers are subject to criteria pollutant standards.

(e) Alternate phase-in standards for greenhouse gas emissions. Where a manufacturer certifies all of its model year 2013 compression-ignition engines within a given primary intended service class to the applicable alternate standards of this paragraph (e), its compression-ignition engines within that primary intended service class are subject to the standards of this paragraph (e) for model years 2013 through 2016. This means that once a manufacturer chooses to certify a primary intended service class to the standards of this paragraph (e), it is not allowed to opt out of these standards.

(f) [Reserved]

(g) Default deterioration factors for greenhouse gas standards. You may use default deterioration factors (DFs) without performing your own durability emission tests or engineering analysis as follows:

(1) You may use a default additive DF of 0.0 g/hp·hr for CO2 emissions from engines that do not use advanced or off-cycle technologies. If we determine it to be consistent with good engineering judgment, we may allow you to use a default additive DF of 0.0 g/hp·hr for CO2 emissions from your engines with advanced or off-cycle technologies.

(2) You may use a default additive DF of 0.010 g/hp·hr for N2O emissions from any engine through model year 2021, and 0.020 g/hp·hr for later model years.

(3) You may use a default additive DF of 0.020 g/hp·hr for CH4 emissions from any engine.

(h) Advanced-technology credits. If you generate CO2 credits from model year 2020 and earlier engines certified for advanced technology, you may multiply these credits by 1.5.

(i) CO2 credits for low N2O emissions. If you certify your model year 2014, 2015, or 2016 engines to an N2O FEL less than 0.04 g/hp·hr (provided you measure N2O emissions from your emission-data engines), you may generate additional CO2 credits under this paragraph (i). Calculate the additional CO2 credits from the following equation instead of the equation in § 1036.705:

(j) Alternate standards under 40 CFR part 86. This paragraph (j) describes alternate emission standards for loose engines certified under 40 CFR 86.1819-14(k)(8). The standards of § 1036.108 do not apply for these engines. The standards in this paragraph (j) apply for emissions measured with the engine installed in a complete vehicle consistent with the provisions of 40 CFR 86.1819-14(k)(8)(vi). The only requirements of this part that apply to these engines are those in this paragraph (j), §§ 1036.115 through 1036.135, 1036.535, and 1036.540.

(k) Limited production volume allowance under ABT. You may produce a limited number of Heavy HDE that continue to meet the standards that applied under 40 CFR 86.007-11 in model years 2027 through 2029. The maximum number of engines you may produce under this limited production allowance is 5 percent of the annual average of your actual U.S.-directed production volume of Heavy HDE in model years 2023-2025. Engine certification under this paragraph (k) is subject to the following conditions and requirements:

(1) Engines must meet all the standards and other requirements that apply under 40 CFR part 86 for model year 2026. Engine must be certified in separate engine families that qualify for carryover certification as described in § 1036.235(d).

(2) The NOX FEL must be at or below 200 mg/hp·hr. Calculate negative credits as described in § 1036.705 by comparing the NOX FEL to the FTP emission standard specified in § 1036.104(a)(1), with a value for useful life of 650,000 miles. Meet the credit reporting and recordkeeping requirements in §§ 1036.730 and 1036.735.

(3) Label the engine as described in 40 CFR 86.095-35, but include the following alternate compliance statement: “THIS ENGINE CONFORMS TO U.S. EPA REGULATIONS FOR MODEL YEAR 2026 ENGINES UNDER 40 CFR 1036.150(k).”

(l) Credit adjustment for spark-ignition engines and light heavy-duty compression-ignition engines. For greenhouse gas emission credits generated from model year 2020 and earlier spark-ignition and light heavy-duty engines, multiply any banked CO2 credits that you carry forward to demonstrate compliance with model year 2021 and later standards by 1.36.

(m) Infrequent regeneration. For model year 2020 and earlier, you may invalidate any test interval with respect to CO2 measurements if an infrequent regeneration event occurs during the test interval. Note that § 1036.580 specifies how to apply infrequent regeneration adjustment factors for later model years.

(n) Supplying fuel maps. Engine manufacturers not yet subject to standards under § 1036.108 in model year 2021 must supply vehicle manufacturers with fuel maps (or powertrain test results) as described in § 1036.130 for those engines.

(o) Engines used in glider vehicles. For purposes of recertifying a used engine for installation in a glider vehicle, we may allow you to include in an existing certified engine family those engines you modify (or otherwise demonstrate) to be identical to engines already covered by the certificate. We would base such an approval on our review of any appropriate documentation. These engines must have emission control information labels that accurately describe their status.

(p) Transition to Phase 2 CO2 standards. If you certify all your model year 2020 engines within an averaging set to the model year 2021 FTP and SET standards and requirements, you may apply the provisions of this paragraph (p) for enhanced generation and use of emission credits. These provisions apply separately for Medium HDE and Heavy HDE.

(1) Greenhouse gas emission credits you generate with model year 2018 through 2024 engines may be used through model year 2030, instead of being limited to a five-year credit life as specified in § 1036.740(d).

(2) You may certify your model year 2024 through 2026 engines to the following alternative standards:

(q) Confirmatory testing of fuel maps defined in § 1036.505(b). For model years 2021 and later, where the results from Eq. 1036.235-1 for a confirmatory test are at or below 2.0%, we will not replace the manufacturer's fuel maps.

(r) Fuel maps for the transition to updated GEM. (1) You may use fuel maps from model year 2023 and earlier engines for certifying model year 2024 and later engines using carryover provisions in § 1036.235(d).

(2) Compliance testing will be based on the GEM version you used to generate fuel maps for certification. For example, if you perform a selective enforcement audit with respect to fuel maps, use the same GEM version that you used to generate fuel maps for certification. Similarly, we will use the same GEM version that you used to generate fuel maps for certification if we perform confirmatory testing with one of your engine families.

(s) Greenhouse gas compliance testing. Select duty cycles and measure emissions to demonstrate compliance with greenhouse gas emission standards before model year 2027 as follows:

(1) For model years 2016 through 2020, measure emissions using the FTP duty cycle specified in § 1036.512 and the SET duty cycle specified in 40 CFR 86.1362, as applicable.

(2) The following provisions apply for model years 2021 through 2026:

(i) Determine criteria pollutant emissions during any testing used to demonstrate compliance with greenhouse gas emission standards; however, the duty-cycle standards of § 1036.104 apply for measured criteria pollutant emissions only as described in subpart F of this part.

(ii) You may demonstrate compliance with SET-based greenhouse gas emission standards in § 1036.108(a)(1) using the SET duty cycle specified in 40 CFR 86.1362 if you collect emissions with continuous sampling. Integrate the test results by mode to establish separate emission rates for each mode (including the transition following each mode, as applicable). Apply the CO2 weighting factors specified in 40 CFR 86.1362 to calculate a composite emission result.

(t) Model year 2027 compliance date. The following provisions describe when this part 1036 starts to apply for model year 2027 engines:

(1) Split model year. Model year 2027 engines you produce before December 20, 2026 are subject to the criteria standards and related provisions in 40 CFR part 86, subpart A, as described in § 1036.1(a). Model year 2027 engines you produce on or after December 20, 2026 are subject to all the provisions of this part.

(2) Optional early compliance. You may optionally certify model year 2027 engines you produce before December 20, 2026 to all the provisions of this part.

(3) Certification. If you certify any model year 2027 engines to 40 CFR part 86, subpart A, under paragraph (t)(1) of this section, certify the engine family by dividing the model year into two partial model years. The first portion of the model year starts when it would normally start and ends when you no longer produce engines meeting standards under 40 CFR part 86, subpart A, on or before December 20, 2026. The second portion of the model year starts when you begin producing engines meeting standards under this part 1036, and ends on the day your model year would normally end. The following additional provisions apply for model year 2027 if you split the model year as described in this paragraph (t):

(i) You may generate emission credits only with engines that are certified under this part 1036.

(ii) In your production report under § 1036.250(a), identify production volumes separately for the two parts of the model year.

(iii) OBD testing demonstrations apply singularly for the full model year.

(u) Crankcase emissions. The provisions of 40 CFR 86.007-11(c) for crankcase emissions continue to apply through model year 2026.

(v) OBD communication protocol. We may approve the alternative communication protocol specified in SAE J1979-2 (incorporated by reference in § 1036.810) if the protocol is approved by the California Air Resources Board. The alternative protocol would apply instead of SAE J1939 and SAE J1979 as specified in 40 CFR 86.010-18(k)(1). Engines designed to comply with SAE J1979-2 must meet the freeze-frame requirements in § 1036.110(b)(8) and in 13 CCR 1971.1(h)(4.3.2) (incorporated by reference in § 1036.810). This paragraph (v) also applies for model year 2026 and earlier engines.

(w) Greenhouse gas warranty. For model year 2027 and later engines, you may ask us to approve the model year 2026 warranty periods specified in § 1036.120 for components or systems needed to comply with greenhouse gas emission standards if those components or systems do not play a role in complying with criteria pollutant standards.

(x) Powertrain testing for criteria pollutants. You may apply the powertrain testing provisions of § 1036.101(b) for demonstrating compliance with criteria pollutant emission standards in 40 CFR part 86 before model year 2027.

(y) NOX compliance allowance for in-use testing. A NOX compliance allowance of 15 mg/hp·hr applies for any in-use testing of Medium HDE and Heavy HDE as described in subpart E of this part. Add the compliance allowance to the NOX standard that applies for each duty cycle and for off-cycle testing, with both field testing and laboratory testing. The NOX compliance allowance does not apply for the bin 1 off-cycle standard. As an example, for manufacturer-run field-testing of a Heavy HDE, add the 15 mg/hp·hr compliance allowance and the 5 mg/hp·hr accuracy margin from § 1036.420 to the 58 mg/hp·hr·bin 2 off-cycle standard to calculate a 78 mg/hp·hr NOX standard.

(z) Alternate family pass criteria for in-use testing. The following family pass criteria apply for manufacturer-run in-use testing instead of the pass criteria described in § 1036.425 for model years 2027 and 2028:

(1) Start by measuring emissions from five engines using the procedures described in subpart E of this part and § 1036.530. If four or five engines comply fully with the off-cycle bin standards, the engine family passes and you may stop testing.

(2) If exactly two of the engines tested under paragraph (z)(1) of this section do not comply fully with the off-cycle bin standards, test five more engines. If these additional engines all comply fully with the off-cycle bin standards, the engine family passes and you may stop testing.

(3) If three or more engines tested under paragraphs (z)(1) and (2) of this section do not comply fully with the off-cycle bin standards, test a total of at least 10 but not more than 15 engines. Calculate the arithmetic mean of the bin emissions from all the engine tests as specified in § 1036.530(g) for each pollutant. If the mean values are at or below the off-cycle bin standards, the engine family passes. If the mean value for any pollutant is above an off-cycle bin standard, the engine family fails.