(a) No person may sell, introduce, cause, or permit the sale or introduction of gasoline containing greater than 10 volume percent ethanol (e.g., E15) into any model year 2000 or older light-duty gasoline motor vehicle, any heavy-duty gasoline motor vehicle or engine, any highway or off-highway motorcycle, or any gasoline-powered nonroad engine, vehicle, or equipment.

(b) Paragraph (a) of this section does not prohibit a person from producing, selling, introducing, causing, or allowing the sale or introduction of gasoline containing greater than 10 volume percent ethanol into any flex-fuel vehicle or flex-fuel engine.