Maximum authorised mass (MAM) means the weight of a vehicle or trailer including the maximum load that can be carried safely when it’s being used on the road.
This is also known as gross vehicle weight (GVW) or permissible maximum weight.
It will be listed in the owner’s 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.