View all text of Subpart B [§ 1042.101 - § 1042.145]

§ 1042.104 - Exhaust emission standards for Category 3 engines.

(a) Duty-cycle standards. Exhaust emissions from your engines may not exceed emission standards, as follows:

(1) Measure emissions using the test procedures described in subpart F of this part. Note that while no PM standards apply for Category 3 engines, PM emissions must be measured for certification testing and reported under § 1042.205. Note also that you are not required to measure PM emissions for other testing.

(2) NOX standards apply based on the engine's model year and maximum in-use engine speed as shown in the following table:

Table 1 to § 1042.104 - NOX Emission Standards for Category 3 Engines


Emission standards Model year Maximum in-use engine speed
Less than 130 RPM 130-2000 RPM aOver 2000 RPM
Tier 12004-201017.045.0·n(−0.20)9.8
Tier 22011-201514.444.0·n(−0.23)7.7
Tier 3 b2016 and later3.49.0·n(−0.20)2.0

a Applicable standards are calculated from n (maximum in-use engine speed, in RPM, as specified in § 1042.140). Round the standards to one decimal place.

b For engines designed with on-off controls as specified in § 1042.115(g), the Tier 2 standards continue to apply any time the engine has disabled its Tier 3 NOX emission controls.

(3) The HC standard for Tier 2 and later engines is 2.0 g/kW-hr. This standard applies as follows:

(i) Alcohol-fueled engines must comply with HC standards based on THCE emissions.

(ii) Natural gas-fueled engines must comply with HC standards based on NMHC emissions.

(iii) Diesel-fueled and all other engines not described in paragraph (a)(3)(i) or (ii) of this section must comply with HC standards based on THC emissions.

(4) The CO standard for Tier 2 and later engines is 5.0 g/kW-hr.

(b) Averaging, banking, and trading. Category 3 engines are not eligible for participation in the averaging, banking, and trading (ABT) program as described in subpart H of this part.

(c) Mode caps. Measured NOX emissions from Tier 3 engines may not exceed the cap specified in this paragraph (c) for any applicable duty-cycle test modes with power greater than 10 percent maximum engine power. Calculate the mode cap by multiplying the applicable Tier 3 NOX standard by 1.5 and rounding to the nearest 0.1 g/kW-hr. Note that mode caps do not apply for pollutants other than NOX and do not apply for any modes of operation outside of the applicable duty cycles in § 1042.505. Category 3 engines are not subject to not-to-exceed standards.

(d) Useful life. Your engines must meet the exhaust emission standards of this section over their full useful life, expressed as a period in years or hours of engine operation, whichever comes first.

(1) The minimum useful life value is 3 years or 10,000 hours of operation.

(2) Specify a longer useful life in hours for an engine family under either of two conditions:

(i) If you design, advertise, or market your engine to operate longer than the minimum useful life (your recommended hours until rebuild indicates a longer design life).

(ii) If your basic mechanical warranty is longer than the minimum useful life.

(e) Applicability for testing. The duty-cycle emission standards in this section apply to all testing performed according to the procedures in § 1042.505, including certification, production-line, and in-use testing. See paragraph (g) of this section for standards that apply for certain other test procedures, such as some production-line testing.

(f) Domestic engines. Engines installed on vessels excluded from 40 CFR part 1043 because they operate only domestically may not be certified for use with residual fuels.

(g) Alternate installed-engine standards. NOX emissions may not exceed the standard specified in this paragraph (g) for test of engines installed on vessels when you are unable to operate the engine at the test points for the specified duty cycle, and you approximate these points consistent with the specifications of section 6 of Appendix 8 to the NOX Technical Code (incorporated by reference in § 1042.910). Calculate the alternate installed-engine standard by multiplying the applicable NOX standard by 1.1 and rounding to the nearest 0.1 g/kW-hr.

[75 FR 22997, Apr. 30, 2010; 81 FR 74145, Oct. 25, 2016; 86 FR 34508, June 29, 2021]