(a) You must show that vehicles meet the following emission standards:

(1) Exhaust emissions of criteria pollutants. Criteria pollutant standards for NOX, HC, PM, and CO apply as described in § 1037.102. These pollutants are sometimes described collectively as “criteria pollutants” because they are either criteria pollutants under the Clean Air Act or precursors to the criteria pollutants ozone and PM.

(2) [Reserved]

(3) Fuel evaporative and refueling emissions. Requirements related to fuel evaporative and refueling emissions are described in § 1037.103.

(b) The regulated heavy-duty vehicles are addressed in different groups as follows:

(1) For criteria pollutants, vehicles are regulated based on gross vehicle weight rating (GVWR), whether they are considered “spark-ignition” or “compression-ignition,” and whether they are first sold as complete or incomplete vehicles.

(2) [Reserved]

(3) For evaporative and refueling emissions, vehicles are regulated based on the type of fuel they use. Vehicles fueled with volatile liquid fuels or gaseous fuels are subject to evaporative and refueling emission standards.

[88 FR 4635, Jan. 24, 2023, as amended at 89 FR 29765, Apr. 22, 2024; 91 FR 7786, Feb. 18, 2026]