Guides & Diagrams

Trailer guides and diagrams that you may find useful are below in addition to some helpful links.

Common Trailer and Towing Terminology

Unladen Weight	The base weight of the vehicle or trailer, excluding any payload, removable accessories, or optional equipment.
Gross Weight	The total actual weight of the trailer (or towing vehicle) plus whatever load it is currently carrying.
Gross Vehicle Weight (GVW) / Gross Vehicle Mass (GVM)	The total combined weight of a towing vehicle and its current load.
Maximum Gross Weight	The maximum weight limit specified by the manufacturer. This is typically the technically permissible limit based on component strength, though it is sometimes adjusted downwards for commercial classification.
Technically Permissible Maximum Weight	The absolute maximum weight the vehicle can handle based strictly on the physical load limits of its tyres, axles, coupling, suspension, and chassis.
Maximum Authorised Mass (MAM)	The modern EC regulatory term for Maximum Gross Weight, used predominantly in driver licensing and law.
Gross Train Weight (GTW)	The maximum legally permitted combined weight of the towing vehicle and the trailer together, as dictated by the towing vehicle’s manufacturer.
Payload	The vehicle or trailer’s maximum load-carrying capacity (calculated as Gross Weight minus Unladen Weight).
Kerb Weight	The weight of the towing vehicle without any payload, but fully fueled and supplied with all necessary operating fluids.
Wheelbase	The distance between the center points of the front and rear wheels along the length of a multi-axle vehicle or trailer.