40 C.F.R. § 1037.5
Excluded vehicles
Except for the definitions specified in § 1037.801, this part does not apply to the following vehicles:
(a) Parts 1065 and 1066 of this chapter describe procedures and equipment specifications for testing engines and vehicles to measure exhaust emissions. Subpart F of this part 1037 describes how to apply the testing provisions of 40 CFR parts 1065 and 1066.
(b) Vehicles excluded from the definition of “heavy-duty vehicle” in § 1037.801 because of vehicle weight, weight rating, and frontal area (such as light-duty vehicles and light-duty trucks).
(c) Vehicles produced in model years before 2014, unless they were certified under § 1037.150.
(d) Medium-duty passenger vehicles and other vehicles subject to the light-duty greenhouse gas standards of 40 CFR part 86. See 40 CFR 86.1818 for greenhouse gas standards that apply for these vehicles. An example of such a vehicle would be a vehicle meeting the definition of “heavy-duty vehicle” in § 1037.801 and 40 CFR 86.1803, but also meeting the definition of “light truck” in 40 CFR 86.1818-12(b)(2).
(e) Vehicles subject to emission standards under 40 CFR part 86, subpart S.
(f) Aircraft meeting the definition of “motor vehicle”. For example, this would include certain convertible aircraft that can be adjusted to operate on public roads. Standards apply separately to certain aircraft engines, as described in 40 CFR part 87.
(g) Where it is unclear, you may ask us to make a determination regarding the exclusions identified in this section. We recommend that you make your request before you produce the vehicle.