Towing capacity: what is permitted?
Legal basics and technical guidance
The permitted towing capacity is listed in your vehicle’s registration certificate (Part I) – in fields O.1 (unbraked) and O.2 (braked). The actual gross weight of the trailer must not exceed these values. This is not only a legal requirement but also a safety issue: an overloaded tow vehicle brakes worse, reacts more sluggishly and is more prone to swaying.
The hitch load (also called nose weight) is especially important: it describes the weight the trailer exerts vertically on the tow ball. The permitted hitch load of the tow vehicle (in the vehicle data sheet, line S) should be utilized at 50–100%. Too little hitch load makes the trailer tail-heavy and increases the tendency to sway, which can become dangerous at higher speeds.
Unbraked trailers (without an overrun brake) are limited to a maximum gross weight of 750 kg or half the tow vehicle’s unladen weight, whichever is lower. Braked trailers with an overrun brake may weigh up to the registered braked towing capacity. Caravans, heavy boat trailers and horse trailers are almost always fitted with an overrun brake.