Gross vehicle mass (GVM)

Gross vehicle mass is the maximum a vehicle is allowed to weigh fully loaded, set by the manufacturer, and it is the number that decides whether a vehicle is legally light or heavy in Australia.

The 4.5 tonne GVM line matters everywhere: above it the Heavy Vehicle National Law applies (outside WA and the NT), heavy vehicle on-road fuel tax credits become claimable, and different licensing and inspection rules kick in.

GVM is the vehicle alone. For a truck towing a trailer, the combined limit is the gross combination mass.

Last updated 10 July 2026. General information, not tax or legal advice.