Heavy-duty vehicle
Heavy-duty vehicle means any motor vehicle rated at more than 8,500 pounds GVWR or that has a vehicle curb weight of more than 6,000 pounds or that has a basic vehicle frontal area in excess of 45 square feet.
Source
40 CFR § 86.082-2
Scoping language
The definitions of this section apply to this subpart and also to subparts B, D, I, and R of this part.