Caravan terms

Also known as the Maximum Authorised Mass (MAM), stated by the caravan manufacturer on the caravan weight plate (normally mounted close to the entrance door but can be mounted anywhere on the external skin (some manufacturers are now mounting them inside the gas locker) - the absolute maximum weight that the caravan must not exceed to be legal on the road. It includes allowances for the user payload - all fluids (water etc) and personal belongings that you may wish to carry (clothes, food etc).

Mass of the caravan equipped to the manufacturer's standard specification stated on the caravan weight plate. From 2011 an NCC Approved caravan will have an allowance in the MRO for basic equipment such as gas bottles, water in the water heater and central heating system, water in any water storage tanks, any essential fluids and the electrical hook-up cable. In older caravans the equipment included in the MRO will be different, so check your handbook for what is included.

Payload relates to the weights of all items carried in a caravan and is the allowance you have for, equipment, including any equipment fitted by the dealer; and Personal effects. The total of the allowances represents the difference between the MTPLM and the MRO.

Items made available by the manufacturer or dealer over and above the standard specification of the caravan, e.g. spare wheel, air conditioning, caravan mover, awning etc.

Those items which you choose to carry in a caravan and which are not included in the MRO or optional equipment. (e.g. clothes, crockery, cooking utensils, bedding, portable TV, portable radio, footwear, books, awning and food.)

The actual weight of the caravan when you use it - including its optional equipment and your personal effects. You need to know this weight because it will determine whether you are legally or illegally towing and also within your caravan towing experience.

The maximum vertical static load that the towing coupling can bear, stamped on a plate on the coupling. See also the caravan drawbar limit, sometimes printed in the owner's manual.

The height of the centre of the coupling hitch should lie in the range of 385mm to 455mm above ground level with the caravan laden and level front to back.

Vehicle terms

Some manufacturers define this figure with or without a driver and with the car in working order (with fuel and fluids). Towsafe kerb weight includes a 68 kg allowance for the weight of a driver and a 7 kg allowance for their luggage.

The maximum allowable weight of the car when fully loaded. When towing, this will include the noseweight of the caravan. The maximum weight is found stamped on your vehicle's weight plate (VIN), it must not be exceeded!

This is the total weight of the tractor unit (your car) plus trailer plus load. (your caravan). The maximum gross train weight is found stamped on your vehicle's weight plate (VIN) , it must not be exceeded!

This figure is often quoted in the manufactures handbook, it is often the same as GTW-GVM; meaning that even if your car has not reached GVW you cannot add any unused vehicle capacity to your trailer load as you will be in breach of your vehicles warranty.

The maximum weight of an unbraked trailer, it should not exceed 750kg or 50% of the kerb weight of your vehicle, which ever is less.

The maximum downforce allowed on a car's towball in kg. The actual maximum noseweight of any vehicle/trailer combination is limited then by the cars noseweight, or the hitch limit of the caravan or the towbar limit, whichever is least.