(a) A heavy-duty vehicle is any commercial medium- and heavy-duty on highway vehicle or a work truck, as defined in 49 U.S.C. 32901(a)(7) and (19). For the purpose of this part, heavy-duty vehicles are divided into three regulatory categories as follows:
(1) Heavy-duty pickup trucks and vans;
(2) Heavy-duty vocational vehicles; and
(3) Truck tractors with a GVWR above 26,000 pounds.
(b) The heavy-duty vehicle classification does not include:
(1) Vehicles defined as medium duty passenger vehicles.
(2) Vehicles excluded from the definition of ``heavy-duty vehicle'' because of vehicle weight or weight rating (such as light duty vehicles as defined in Sec. 523.5).
(3) Vehicles excluded from the definition of motor vehicle in 40 CFR 85.1703. [76 FR 57491, Sept. 15, 2011]