California Code, Health and Safety Code - HSC § 43800

(a) Is capable of operating on methanol, as determined by the state board, and will have an adverse impact on ambient ozone air quality not greater than a vehicle which meets the requirements of subdivision (c).

(b) Is capable of operating on any available fuel other than gasoline or diesel and, in the determination of the state board, will have an adverse impact on ambient ozone air quality not greater than a vehicle operating on methanol.

(c) Operates exclusively on gasoline and is certified to meet a hydrocarbon exhaust emission standard which is at least twice as stringent as otherwise applicable to gasoline vehicles of the same year and class.

(d) Is capable, in the case of a heavy-duty diesel vehicle, of meeting standards for either oxides of nitrogen or particulate matter that are twice as stringent as otherwise applicable.