If you are going to purchase a trailer or caravan, it is critical that you give careful consideration to your vehicle’s towing mass and construction prior to making your purchase.
You will find the towing mass (or towing rating) under the towing section in the vehicle manufacturer’s handbook. The rating will include a trailer weight capacity and a trailer ball weight capacity, both of which must not be exceeded. If the manufacturer has not stipulated a recommended tow mass, then the vehicle may tow one and a half times its unladen mass if the trailer has brakes.
If no brakes are fitted, then 750kgs is the maximum permissible towing capacity.
With regards to tow vehicles, the towbar fitted must not exceed the capacity approved by the vehicle manufacturer. In some cases some additional (strengthening) materials are supplied with the certified towbar as part of the fitting kit. It may also be advisable to fit additional towing aids to enhance towing compatibility and safety.
These could include:
- Weight distribution hitches (sometimes colloquially called level rides). Seek expert advice on this type of equipment. Such devices should not be used with over-ride brakes.
- Fitting load levelling devices (frequently called weight distributing hitches or level rides). These must not be used with override brakes.
- Fitting a suitable brake controller and connection: all trailers of 750kgs GTM or more must be fitted with brakes. Electric brakes are the most commonly used and require a brake controller, with appropriate connections to the trailer, to be fitted in the tow vehicle.
- Extra mirrors may need to be added to the tow vehicle when towing large trailers. It is a legal requirement that the driver has a clear and unobstructed view of the road to the rear of the vehicle or vehicle combination at all times.
- Fitting an extra transmission oil cooler for vehicles with automatic transmission. These are standard on some late model vehicles.
- As some motor vehicle manufacturers limit the speed at which you can tow a trailer always refer to the vehicle handbook.
Remember that towing a trailer or caravan will decrease your vehicle’s acceleration and braking performance. It will also reduce vehicle control and manoeuvrability, while increasing fuel consumption.
Your vehicle’s towing capacity is a factor of its engine size, brakes, weight, transmission, tyres, bearings, chassis, suspension etc.
After taking these variables into account, the vehicle’s manufacturer establishes a recommended towing capacity, which is the legal maximum and must not be exceeded.