Vehicle weights explained
Vehicle categories on driving licences can depend on the weight of the vehicle – the different terms you might see are explained below.
Unladen weight
The unladen weight of any vehicle is the weight of the vehicle when itÂs not carrying any passengers, goods or other items.
It includes the body and all parts normally used with the vehicle or trailer when itÂs used on a road.
It doesnÂt include the weight of the fuel or, if itÂs an electric vehicle, the batteries.
Maximum authorised mass
Maximum authorised mass (MAM) means the weight of a vehicle or trailer including the maximum load that can be carried safely when itÂs being used on the road.
This is also known as gross vehicle weight (GVW) or permissible maximum weight.
It will be listed in the ownerÂs manual and is normally shown on a plate or sticker fitted to the vehicle.
The plate or sticker may also show a gross train weight (GTW), also sometimes called gross combination weight (GCW). This is the total weight of the tractor unit plus trailer plus load.
Down-plating
If a vehicle is unlikely to be used at its potential maximum weight, it may be Âdown-platedÂ. This means that a lower weight is shown on the plate or sticker attached to the vehicle.