(a) The Clean Air Act includes provisions intended to promote the development and sale of clean-fuel vehicles (see 42 U.S.C. 7581-7589). This takes the form of credit incentives for State Implementation Plans. The specified clean-fuel vehicle standards to qualify for these credits are now uniformly less stringent than the emission standards that apply for new vehicles and new engines under 40 CFR parts 86 and 1036.

(b) The following provisions apply for purposes of State Implementation Plans that continue to reference the Clean Fuel Fleet Program:

(1) Vehicles and engines certified to current emission standards under 40 CFR part 86 or 1036 are deemed to also meet the Clean Fuel Fleet standards as Ultra Low-Emission Vehicles.

(2) Vehicles and engines meeting requirements as specified in paragraph (a)(1) of this section with a fuel system designed to not vent fuel vapors to the atmosphere are also deemed to meet the Clean Fuel Fleet standards as Inherently Low-Emission Vehicles. This paragraph (b)(2) applies for vehicles using diesel fuel, liquefied petroleum gas, or compressed natural gas. It does not apply for vehicles using gasoline, ethanol, methanol, or liquefied natural gas.

(3) The following types of vehicles qualify as Zero Emission Vehicles:

(i) Electric vehicles (see 40 CFR 86.1803-01).

(ii) Any other vehicle with a fuel that contains no carbon or nitrogen compounds, that has no evaporative emissions, and that burns without forming oxides of nitrogen, carbon monoxide, formaldehyde, particulate matter, or hydrocarbon compounds. This paragraph (b)(3)(i) applies equally for all engines installed on the vehicle.