Every vehicle manufacturer has to give a maximum towing limit. This can be found in the vehicle handbook and also on the chassis plate, usually found under the bonnet.
The information can be presented in a variety of ways. The clearest is when the plate gives the towing limits for both braked and unbraked trailers.
Sometimes the car’s Gross Train Weight (GTW) is given. This is the combination of the car’s Maximum Permitted weight (MPW) sometimes called Gross Vehicle Weight (GVW) and the trailers Gross Trailer Weight. To get the towing limit simply deduct the MPW from the GTW. It is an offence to exceed the car’s towing limit.
The VIN plate will display either 3 or 4 sets of weights, it is these weights that VOSA or the other vehicle authorities use to determine whether your vehicle is towing or being driven within the law.
- The top figure ‘A’ is the gross vehicle weight, the Maximum Allowable Mass (MAM) of the vehicle including occupants, fuel and payload.
- The second figure ‘B’ is the gross train weight, this is the combined maximum allowable mass of the vehicle and trailer.
- The third and fourth figures ‘C’ and ‘D’ are maximum axle loads front and rear respectively.
The manufacturer’s recommended maximum towing capacity for your vehicle is the gross vehicle weight subtracted from gross train weight. (4200kg – 2505kg = 1695Kg)
This calculation is based on a fully laden vehicle.
Certain performance, hybrid and city-car models or similar variants of standard models are not homologated to tow, this means that the vehicle manufacturer has deemed that the model is unsuitable for use as a tow vehicle. With this type of vehicle, the towing capacity will equate to zero or a gross train weight will not be displayed.