• Unladen weight

the weight of the trailer (or towing vehicle) less removable optional equipment and load.

• Gross weight

the total weight of the trailer (or towing vehicle) and load.

• Gross Vehicle Weight (GVW)

the total weight of the towing vehicle and its load.

• Gross Vehicle Mass (GVM)

the total weight of the towing vehicle and its load.

• Maximum Gross Weight

the maximum figure set by the manufacturer for the gross weight. This will normally be the technically permissible maximum based on the carrying capacity of the tyres, axles, coupling, suspension and chassis but may have been adjusted downwards for commercial reasons

• Technically Permissible Maximum Weight

the technically permissible maximum based on the carrying capacity of the tyres, axles, coupling, suspension and chassis.

• Maximum Authorised Mass( MAM )

as maximum gross weight above. The latest EC term as used in the driver licensing regulations.

• Gross Train Weight (GTW )

the maximum allowable combined weight (combined MAM) of the towing vehicle and trailer as set by the towing vehicle manufacturer.

• Payload

the difference between the gross weight of the trailer and its unladen weight: i.e., the load carrying capacity.

• Kerb weight (kerbside weight)

the weight of the towing vehicle (without payload) including all fluids required for operation.

• Vertical static load (nose weight)

the weight imposed on the towball or eye by the trailer coupling.

• Overrun braking system

a trailer braking system operated by the action of the trailer bearing on the towing vehicle under deceleration.

• Power operated braking system

a trailer braking system which is operated directly by the action of the foot brake on the towing vehicle.

• Wheel track

horizontal distance between the centrelines of the wheels across the width of the vehicle or trailer.

• Wheelbase

horizontal distance between the centrelines of the wheels of multi-axle vehicles or trailers along the length of the vehicle.