§86.008-10. Emission standards for 2008 and later model year Otto-cycle heavy-duty engines and vehicles.
40 C.F.R. § 86.008-10
This section applies to new 2008 and later model year Otto-cycle heavy-duty engines and vehicles. Starting in model year 2021, this section applies to light HDE and medium HDE, but it no longer applies to heavy HDE (see 40 CFR 1036.140(a) and 1036.150(c)).
Exhaust emissions from new 2008 and later model year Otto-cycle HDEs shall not exceed:
Oxides of Nitrogen (NO— X). 0.20 grams per brake horsepower-hour (0.075 grams per megajoule).
A manufacturer may elect to include any or all of its Otto-cycle HDE families in any or all of the NOX and NOX plus NMHC emissions ABT programs for HDEs, within the restrictions described in § 86.008-15 or § 86.004-15. If the manufacturer elects to include engine families in any of these programs, the NOX FEL may not exceed 0.50 grams per brake horsepower-hour (0.26 grams per megajoule). This ceiling value applies whether credits for the family are derived from averaging, banking, or trading programs. The NOX FEL cap is 0.80 for model years before 2011 for manufacturers choosing to certify to the 1.5 g/bhp-hr NOX + NMHC standard in 2003 or 2004, in accordance with § 86.005-10(f).
Nonmethane hydrocarbon (NMHC) for engines fueled with gasoline. 0.14 grams per brake horsepower-hour (0.052 grams per megajoule).
Nonmethane-nonethane hydrocarbon (NMNEHC) for engines fueled with natural gas or liquefied petroleum gas. 0.14 grams per brake horsepower-hour (0.052 grams per megajoule).
Nonmethane hydrocarbon equivalent (NMHCE) for engines fueled with methanol. 0.14 grams per brake horsepower-hour (0.052 grams per megajoule).
A manufacturer may elect to include any or all of its Otto-cycle HDE families in any or all of the hydrocarbon emission ABT programs for HDEs, within the restrictions described in § 86.007-15 or § 86.004-15. If the manufacturer elects to include engine families in any of these programs, the hydrocarbon FEL may not exceed 0.30 grams per brake horsepower-hour. This ceiling value applies whether credits for the family are derived from averaging, banking, or trading programs. The hydrocarbon FEL cap is 0.40 for model years before 2011 for manufacturers choosing to certify to the 1.5 g/bhp-hr NOX + HC in 2004, as allowed in § 86.005-10.
Carbon monoxide. 14.4 grams per brake horsepower-hour (5.36 grams per megajoule).
Particulate. 0.01 grams per brake horsepower-hour (0.0037grams per megajoule).
The standards set forth in paragraph (a)(1) of this section refer to the exhaust emitted over the operating schedule set forth in paragraph (f)(1) of Appendix I to this part, and measured and calculated in accordance with the procedures set forth in subpart N or P of this part:
Perform the test interval set forth in paragraph (f)(1) of Appendix I of this part with a cold-start according to 40 CFR part 1065, subpart F. This is the cold-start test interval.
Shut down the engine after completing the test interval and allow 20 minutes to elapse. This is the hot soak.
Repeat the test interval. This is the hot-start test interval.
Calculate the total emission mass of each constituent, m, and the total work, W, over each test interval according to 40 CFR 1065.650.
Determine your engine's brake-specific emissions using the following calculation, which weights the emissions from the cold-start and hot-start test intervals:
-(4) [Reserved]
This paragraph (b) applies as specified in 40 CFR 1037.103. Evaporative emissions from heavy-duty vehicles shall not exceed the following standards when measured using the test procedures specified in 40 CFR 1037.501. The standards apply equally to certification and in-use vehicles. The spitback standard also applies to newly assembled vehicles. For certification vehicles only, manufacturers may conduct testing to quantify a level of nonfuel background emissions for an individual test vehicle. Such a demonstration must include a description of the source(s) of emissions and an estimated decay rate. The demonstrated level of nonfuel background emissions may be subtracted from emission test results from certification vehicles if approved in advance by the Administrator.
Hydrocarbons (for vehicles equipped with gasoline-fueled, natural gas-fueled or liquefied petroleum gas-fueled engines).
For vehicles with a Gross Vehicle Weight Rating of up to 14,000 lbs—
(1) For the full three-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements: 1.4 grams per test.
(2) For the supplemental two-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements (gasoline-fueled vehicles only): 1.75 grams per test.
Running loss test (gasoline-fueled vehicles only)— 0.05 grams per mile.
Fuel dispensing spitback test (gasoline-fueled vehicles only)— 1.0 grams per test.
For vehicles with a Gross Vehicle Weight Rating of greater than 14,000 lbs—
(1) For the full three-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements: 1.9 grams per test.
(2) For the supplemental two-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements (gasoline-fueled vehicles only): 2.3 grams per test.
Running loss test (gasoline-fueled vehicles only)— 0.05 grams per mile.
Total Hydrocarbon Equivalent (for vehicles equipped with methanol-fueled engines).
For vehicles with a Gross Vehicle Weight Rating of up to 14,000 lbs—
(1) For the full three-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements: 1.4 grams carbon per test.
(2) For the supplemental two-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements: 1.75 grams carbon per test.
Running loss test— 0.05 grams carbon per mile.
Fuel dispensing spitback test— 1.0 grams carbon per test.
For vehicles with a Gross Vehicle Weight Rating of greater than 14,000 lbs—
(1) For the full three-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements: 1.9 grams carbon per test.
(2) For the supplemental two-diurnal test sequence described in § 86.1230-96, diurnal plus hot soak measurements: 2.3 grams carbon per test.
Running loss test— 0.05 grams carbon per mile.
For vehicles with a Gross Vehicle Weight Rating of up to 26,000 lbs, the standards set forth in paragraphs (b)(1) and (b)(2) of this section refer to a composite sample of evaporative emissions collected under the conditions and measured in accordance with the procedures set forth in subpart M of this part.
For vehicles with a Gross Vehicle Weight Rating of greater than 26,000 lbs., the standards set forth in paragraphs (b)(1)(ii) and (b)(2)(ii) of this section refer to the manufacturer's engineering design evaluation using good engineering practice (a statement of which is required in § 86.098-23(b)(4)(ii)).
All fuel vapor generated in a gasoline- or methanol-fueled heavy-duty vehicle during in-use operations shall be routed exclusively to the evaporative control system (e.g., either canister or engine purge). The only exception to this requirement shall be for emergencies.
Compressed natural gas vehicles must meet the requirements for fueling connection devices as specified in § 86.1813-17(f)(1). Vehicles meeting these requirements are deemed to comply with evaporative emission standards.
No crankcase emissions shall be discharged into the ambient atmosphere from any new 2008 or later model year Otto-cycle HDE.
Every manufacturer of new motor vehicle engines subject to the standards prescribed in this section shall, prior to taking any of the actions specified in section 203(a)(1) of the Act, test or cause to be tested motor vehicle engines in accordance with applicable procedures in subpart N or P of this part to ascertain that such test engines meet the requirements of this section.
The standards described in this section do not apply to Otto-cycle medium-duty passenger vehicles (MDPVs) that are subject to regulation under subpart S of this part, except as specified in subpart S of this part. The standards described in this section also do not apply to Otto-cycle engines used in such MDPVs, except as specified in subpart S of this part. The term “medium-duty passenger vehicle” is defined in § 86.1803.
[Reserved]
Model years 2018 through 2026 engines that will be installed in specialty vehicles as allowed by 40 CFR 1037.605 may meet alternate emission standards as follows:
The engines must be of a configuration that is identical to one that is certified under 40 CFR part 1048 to the Blue Sky standards under 40 CFR 1048.140.
Except as specified in this paragraph (g), engines certified under this paragraph (g) must meet all the requirements that apply under 40 CFR part 1048 instead of the comparable provisions in this subpart A. Before shipping engines under this section, you must have written assurance from the vehicle manufacturers that they need a certain number of exempted engines under this section. In your annual production report under 40 CFR 1048.250, count these engines separately and identify the vehicle manufacturers that will be installing them. Treat these engines as part of the corresponding engine family under 40 CFR part 1048 for compliance purposes such as testing production engines, in-use testing, defect reporting, and recall.
The engines must be labeled as described in § 86.095-35, with the following statement instead of the one specified in § 86.095-35(a)(3)(iii)(H): “This engine conforms to alternate standards for specialty vehicles under 40 CFR 86.008-10(g)”. Engines certified under this paragraph (g) may not have the label specified for nonroad engines in 40 CFR part 1048 or any other label identifying them as nonroad engines.
In a separate application for a certificate of conformity, identify the corresponding nonroad engine family, describe the label required under this paragraph (g), state that you meet applicable diagnostic requirements under 40 CFR part 1048, and identify your projected U.S.-directed production volume.
No additional certification fee applies for engines certified under this paragraph (g).
Engines certified under this paragraph (g) may not generate or use emission credits under this part.
Engines may instead meet standards for heavy-duty highway engines in California, as demonstrated by an Executive Order issued by the California Air Resources Board.
Notes, amendments, and revision history
Amendments
[66 FR 5165, Jan. 18, 2001, as amended at 75 FR 22978, Apr. 30, 2010; 79 FR 23689, Apr. 28, 2014; 81 FR 73975, Oct. 25, 2016; 88 FR 4474, Jan. 24, 2023; 91 FR 7760, Feb. 18, 2026]
Source
Source: 42 FR 32907, June 28, 1977, unless otherwise noted.
Authority
Authority: 42 U.S.C. 7401-7671q.
Amendments
[66 FR 5165, Jan. 18, 2001, as amended at 75 FR 22978, Apr. 30, 2010; 79 FR 23689, Apr. 28, 2014; 81 FR 73975, Oct. 25, 2016; 88 FR 4474, Jan. 24, 2023; 91 FR 7760, Feb. 18, 2026]