Tax Law, §§ 501(2) 503-a(9)
In this Subchapter, the term motor vehicle will be used as defined in subdivision (a) of this section.
Example 1:
A tractor having an unloaded weight of 3,500 pounds, but a maximum gross weight of 19,000 pounds when used in combination with a trailer, is a motor vehicle.
Example 2:
A semi-trailer having an unloaded weight of 10,000 pounds, but a maximum gross weight of 49,000 pounds when used in combination with a tractor, is a motor vehicle.
Example 3:
A truck having an unloaded weight of 8,500 pounds and a maximum gross weight of 16,000 pounds is a motor vehicle.
Example 4:
A tractor having an unloaded weight of 5,000 pounds and a maximum gross weight of 15,000 pounds, when used in combination with a trailer, is a motor vehicle.
Example 1:
A tow truck, having an unloaded weight of 20,000 pounds pulls a disabled snow plow weighing 35,000 pounds; the tow truck is a motor vehicle.
Example 2:
A tow truck having an unloaded weight of 7,000 pounds pulls a disabled truck weighing 18,500 pounds; the tow truck is not a motor vehicle.
N.Y. Comp. Codes R. & Regs. Tit. 20 § 470.2