(a) This part specifies emission standards for certain vehicles and for certain pollutants. It also summarizes other standards that apply under 40 CFR part 86. This part contains standards and other regulations applicable to the emission of the air pollutant defined as the aggregate group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perflurocarbons, and sulfur hexafluoride.
(b) The regulated emissions are addressed in four groups:
(1) Exhaust emissions of NOX, HC, PM, and CO. 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 pollutant ozone. These pollutants are also sometimes described collectively as ``non-greenhouse gas pollutants'', although they do not necessarily have negligible global warming potential. As described in Sec. 1037.102, standards for these pollutants are provided in 40 CFR part 86.
(2) Exhaust emissions of CO2, CH4, and N2O. These pollutants are described collectively in this part as ``greenhouse gas pollutants'' because they are regulated primarily based on their impact on the climate. These standards are provided in Sec. Sec. 1037.104 through 1037.106.
(3) Hydrofluorocarbons. These pollutants are also ``greenhouse gas pollutants'' but are treated separately from exhaust greenhouse gas pollutants listed in paragraph (b)(2) of this section. These standards are provided in Sec. 1037.115.
(4) Fuel evaporative emissions. These requirements are described in 40 CFR part 86 and Sec. 1037.103.
(c) 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. These groupings apply as described in 40 CFR part 86.
(2) For greenhouse gas pollutants, vehicles are regulated in the following groups:
(i) Complete and certain incomplete vehicles at or below 14,000 pounds GVWR (see Sec. 1037.104 for further specification). Certain provisions of 40 CFR part 86 apply for these vehicles; see Sec. 1037.104(h) for a list of provisions in this part 1037 that also apply for these vehicles. These provisions may also be optionally applied to certain other vehicles, as described in Sec. 1037.104.
(ii) Tractors above 26,000 pounds GVWR.
(iii) All other vehicles subject to standards under this part. These other vehicles are referred to as ``vocational'' vehicles.
(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 emission standards. Vehicles up to a certain size that are fueled with gasoline, diesel fuel, ethanol, methanol, or LPG are subject to refueling emission standards. [76 FR 57398, Sept. 15, 2011, as amended at 79 FR 23749, Apr. 28, 2014]