Stützlast

Stützlast, in German often referred to as the tongue or hitch load, is the vertical load transmitted from a trailer to the towing vehicle through the coupling. It represents the downward force acting on the hitch ball and is expressed in kilograms (kg). This load is distinct from the horizontal towing force (Zuglast) and influences the rear axle loading and overall vehicle stability.

Each combination of vehicle and tow hitch has a maximum permissible Stützlast. This value is specified in the vehicle’s type approval and usually also on the hitch or in the owner’s manual. The actual allowable Stützlast for a given setup is the lesser of the vehicle’s limit and the hitch’s limit. The trailer’s tongue weight should not exceed this permissible value to maintain safe handling and structural integrity.

Typical values vary widely. For many passenger cars, Stützlast is in the range of 50–100 kg; mid-size SUVs often 100–150 kg; some heavy-duty vehicles and higher-rated hitches can handle more, up to around 200 kg or more. The precise value depends on the vehicle, the hitch, and compliance with the trailer’s design.

Practical considerations: excessive Stützlast can reduce stability, increase braking distance, alter steering behavior, and place excessive stress on suspension and the hitch. A common guideline is that tongue weight amounts to roughly 7–15% of the trailer’s gross weight, though the exact ratio depends on the trailer design and weight distribution.

Measurement and compliance: Stützlast can be measured with scales at the hitch or a weighing system, and must be kept within the specified limits for safe towing. Always verify both vehicle and hitch ratings, and ensure the trailer’s tongue weight is balanced accordingly.