40 CFR 89.1 - Applicability.
(a) This part applies for all compression-ignition nonroad engines (see definition of “nonroad engine” in § 89.2) except those specified in paragraph (b) of this section. This means that the engines for which this part applies include but are not limited to the following:
(3) Portable compression-ignition engines that are used in but not installed in marine vessels (as defined in the General Provisions of the United States Code, 1 U.S.C. 3);
(4) Non-propulsion compression-ignition engines used in locomotives; and
(5) Compression-ignition marine engines with rated power under 37 kW.
(b) (1) Aircraft engines. This part does not apply for engines used in aircraft (as defined in 40 CFR 87.1).
(2) Mining engines. This part does not apply for engines used in underground mining equipment and regulated by the Mining Safety and Health Administration (MSHA) in 30 CFR parts 7, 31, 32, 36, 56, 57, 70, and 75..
(3) Locomotive engines. This part does not apply for engines that:
(i) Are subject to the standards of 40 CFR part 92; or
(4) Marine engines. This part does not apply for engines that:
(i) Are subject to the standards of 40 CFR part 94;
(5) Hobby engines. This part does not apply for engines installed in reduced-scale models of vehicles that are not capable of transporting a person.
(6) Tier 4 engines. This part does not apply to engines that are subject to emission standards under 40 CFR part 1039. See 40 CFR 1039.1 to determine when that part 1039 applies. Note that certain requirements and prohibitions apply to engines built on or after January 1, 2006 if they are installed in stationary applications or in equipment that will be used solely for competition, as described in 40 CFR 1039.1 and 40 CFR 1068.1; those provisions apply instead of the provisions of this part 89.
(c) In certain cases, the regulations in this part 89 apply to engines at or above 250 kW that would otherwise be covered by 40 CFR part 1048. See 40 CFR 1048.620 for provisions related to this allowance.