Vehicle Weights Explained | Nidirect

Vehicle weights explained

The different vehicle categories on your driving licence tell you what type of vehicle you are permitted to drive and can be dependent on your age. These categories are set by the weight of the vehicle.

Unladen weight

The unladen weight of any vehicle is the vehicle's own weight when not carrying any goods or burden. This is inclusive of the body and all parts which are necessary or usually used with the vehicle or trailer when working on a road exclusive of fuel and in the case of an electrically powered vehicle, the batteries.

Maximum authorised mass

The term maximum authorised mass (MAM), used in the context of driving licences, is the maximum weight of a vehicle or trailer including the maximum load that can be carried safely while used on the road. This is also known as gross vehicle weight (GVW) or maximum weight allowed.

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).

Down-plating

If a vehicle is unlikely to be used at its potential maximum weight, it may be down-plated, so that a lower weight is given on the plate. The manufacturer should be contacted and a replacement plate sought to reflect the new weights.

Maximum weights

The maximum weights at which vehicles, trailers and articulated combinations can be used are marked on the vehicle's plate or can be found in the owner's manual.

On some vehicles the maximum weights may also be listed on the vehicle registration certificate V5C(NI). If in any doubt the vehicle or trailer manufacturer should be contacted.

More useful links

• How to tell DVA about a medical condition
• The driving licence you need to tow a caravan or trailer
• Buses and lorries you can drive and minimum ages
• Motorcycles, cars and other vehicles you can ride or drive and minimum ages

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