§ 1036.108 - Greenhouse gas emission standards—CO2, CH4, and N2O.

§ 1036.108 Greenhouse gas emission standards—CO₂, CH₄, and N₂O.

Cross Reference

Link to an amendment published at 89 FR 29738, Apr. 22, 2024.

This section contains standards and other regulations applicable to the emission of the air pollutant defined as the aggregate group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. This section describes the applicable CO₂, N₂O, and CH₄ standards for engines.

(a) Emission standards. Emission standards apply for engines and optionally powertrains measured using the test procedures specified in subpart F of this part as follows:

(1) CO₂ emission standards in this paragraph (a)(1) apply based on testing as specified in subpart F of this part. The applicable test cycle for measuring CO₂ emissions differs depending on the engine family's primary intended service class and the extent to which the engines will be (or were designed to be) used in tractors. For Medium HDE and Heavy HDE certified as tractor engines, measure CO₂ emissions using the SET steady-state duty cycle specified in § 1036.510. This testing with the SET duty cycle is intended for engines designed to be used primarily in tractors and other line-haul applications. Note that the use of some SET-certified tractor engines in vocational applications does not affect your certification obligation under this paragraph (a)(1); see other provisions of this part and 40 CFR part 1037 for limits on using engines certified to only one cycle. For Medium HDE and Heavy HDE certified as both tractor and vocational engines, measure CO₂ emissions using the SET duty cycle specified in § 1036.510 and the FTP transient duty cycle specified in § 1036.512. Testing with both SET and FTP duty cycles is intended for engines that are designed for use in both tractor and vocational applications. For all other engines (including Spark-ignition HDE), measure CO₂ emissions using the FTP transient duty cycle specified in § 1036.512.

(i) Spark-ignition standards. The Phase 1 CO₂ standard is 627 g/hp·hr for all spark-ignition engines is 627 g/hp·hr for model years 2016 through 2020.This standard continues to apply in later model years for all spark-ignition engines that are not Heavy HDE. Spark-ignition engines that qualify as Heavy HDE under § 1036.140(b)(2) for model years 2021 and later are subject to the compression-ignition engine standards for Heavy HDE-Vocational or Heavy HDE-Tractor, as applicable. You may certify spark-ignition engines to the compression-ignition standards for the appropriate model year under this paragraph (a). If you do this, those engines are treated as compression-ignition engines for all provisions of this part.

(ii) Compression-ignition standards. The following Phase 1 CO₂ standards apply for compression-ignition engines (in g/hp·hr)and model year 2021 and later spark-ignition engines that qualify as Heavy HDE:

Table 1 to Paragraph (a)(1)(ii) of § 1036.108—Compression-Ignition Engine Standards for Model Years 2014-2020

Model

CO₂ Standards

[g/hp·hr]

Phase	Model years	Light HDE	Medium HDE—vocational	Heavy HDE—vocational	Medium HDE—tractor	Heavy HDE—tractor	HDE- vocational	Heavy HDE- vocational	Medium HDE- tractor	Heavy HDE- tractor
1	2014-2016	600	600	567	502	475
	2017-2020	576	576	555	487	460

(iii) The following Phase Table 2 to Paragraph (a)(1)(iii) of § 1036.108—Compression-Ignition Engine Standards for Model Years

2

CO₂ standards apply for compression-ignition engines and all Heavy HDE (in g/hp·hr):

2021

and LaterModel years Light HDE Medium HDE—vocational Heavy HDE—vocational Medium HDE—tractor Heavy HDE—tractor 2021

-2023	563	545	513	473	447
	2024-2026	555	538	506	461	436
	2027 and later	552	535	503	457	432

(

iv) You may certify spark-ignition engines to the compression-ignition standards for the appropriate model year under this paragraph (a). If you do this, those engines are treated as compression-ignition engines for all the provisions of this part.

(2) The CH₄ emission standard is 0.10 g/hp·hr when measured over the applicable FTP transient duty cycle specified in § 1036.512. This standard begins in model year 2014 for compression-ignition engines and in model year 2016 for spark-ignition engines. Note that this standard applies for all fuel types just like the other standards of this section.

(3) The N₂O emission standard is 0.10 g/hp·hr when measured over the applicable FTP transient duty cycle specified in § 1036.512. This standard begins in model year 2014 for compression-ignition engines and in model year 2016 for spark-ignition engines.

(b) Family Certification Levels. You must specify a CO₂ Family Certification Level (FCL) for each engine family expressed to the same number of decimal places as the emission standard. The FCL may not be less than the certified emission level for the engine family. The CO₂ family emission limit (FEL) for the engine family is equal to the FCL multiplied by 1.03.

(c) Averaging, banking, and trading. You may generate or use emission credits under the averaging, banking, and trading (ABT) program described in subpart H of this part for demonstrating compliance with CO₂ emission standards. Credits (positive and negative) are calculated from the difference between the FCL and the applicable emission standard. As described in § 1036.705, you may use CO₂ credits to certify your engine families to FELs for N₂O and/or CH₄, instead of the N₂O/CH₄ standards of this section that otherwise apply. Except as specified in §§ 1036.150 and 1036.705, you may not generate or use credits for N₂O or CH₄ emissions.

(d) Useful life. The exhaust emission standards of this section apply for the useful life, expressed as vehicle miles, or hours of engine operation, or years in service, whichever comes first, as follows:

Table 3 to Paragraph (d) of § 1036.108—Useful Life by Primary Intended Service Class for Model Year 2021 and Later

Primary intended service class	Miles	Years
Spark-ignition HDEa	150,000	15
Light HDEa	150,000	15
Medium HDE	185,000	10
Heavy HDEb	435,000	10

^a Useful life for Spark-ignition HDE and Light HDE before model year 2021 is 110,000 miles or 10 years, whichever occurs first.

^b Useful life for Heavy HDE is also expressed as 22,000 operating hours. For an individual engine, the useful life is no shorter than 10 years or 100,000 miles, whichever occurs first, regardless of operating hours.

(e) Applicability for testing. The emission standards in this subpart apply as specified in this paragraph (e) to all duty-cycle testing (according to the applicable test cycles) of testable configurations, including certification, selective enforcement audits, and in-use testing. The CO₂ FCLs serve as the CO₂ emission standards for the engine family with respect to certification and confirmatory testing instead of the standards specified in paragraph (a)(1) of this section. The FELs serve as the emission standards for the engine family with respect to all other duty-cycle testing. See §§ 1036.235 and 1036.241 to determine which engine configurations within the engine family are subject to testing. Note that engine fuel maps and powertrain test results also serve as standards as described in §§ 1036.535, 1036.540, 1036.545, and 1036.630 and 40 CFR 1037.550..

[88 FR 4487, Jan. 24, 2023, as amended at 89 FR 29738, Apr. 22, 2024]