How to Tow Safely, Efficiently and Legally

If you’ve recently entered the caravanning community, you may be overwhelmed with advice on how to tow your van – or you might have received no advice at all! If you’re looking for expert advice and a breakdown of the confusing acronyms and terminology that everyone assumes you already know, then you’ve come to the right place.



Wondering what all the new terms mean? Consult this glossary for a simple definition of these new, complex terms.

  • Kerb Weight:
    This is related to the tow vehicle – your car – and is given by the manufacturer. It varies from brand to brand, but generally includes the driver, oil and fuel.
  • Pay Load:
    Take the kerb weight of your vehicle, and add accessories, gear and other passengers. It also includes the weight exerted by the trailer on your cars tow ball.
  • Tare Mass:
    The weight of caravan at the time it was built, including any accessories that are built in, and empty water tanks and empty gas bottles.


The world of towing is filled with acronyms, and the best way to learn what everything means is to see its definition written down in front of you.

  • ATM:
    Aggregate Trailer Mass is set by the caravan manufacturer, and is the maximum weight it can be loaded to, including full water tanks, and accessories such as bikes, solar panels, etc.
  • GCM:
    Gross Combination Mass is the maximum weight of both the van, the vehicle, and their combined payloads.
  • GTM:
    Gross Trailer Mass is calculated when the trailer or caravan is hooked up to the tow vehicle, and represents the weight exerted on the wheels of the van.
  • GVN:
    Gross Vehicle Mass is set by the manufacturer, and is referring to the total your vehicle can weigh. It includes everything from the passengers to the weight on the tow ball from the caravan. It should never be exceeded, for safety and legal reasons.
Keeping it Legal – Weights and Insurance

In Depth Definitions

Some things take a little bit more understanding than others – so we’ve prepared more in-depthdefinitions, so you can have a deeper knowledge.

  • Ball Weight:
    Keeping the ball weight correct and balanced is critical to the stability of whatever you’re towing. Ball weight is the amount of down weight exerted on the tow ball. It should be between 7 to 15% of the ATM. This can be measured with a tow ball scale.
  • Brakes:
    When towing, you may find trailer you’re taking needs additional breaks added to keep you safe. The regulations here are very straightforward – if the trailer weighs under 750kgs, you don’t need brakes. If it weighs between 750 to 2000kg, it needs overrun brakes or electric brakes, and if it weighs over 2000kg, it needs breaks that can be operated from the driver’s seat, as well as a breakaway brake system.
  • Mirrors:
    The legislation on mirrors states that you must have visibility around your vehicle and whatever you are towing. The easiest way to see if you need extended mirrors is to have the caravan lined up directly behind your car, and then stand at the rear corner of your caravan. If you can’t see the entire mirror surface, you need bigger mirrors.


  • You’ll find your vehicles GVN stamped on its compliance plates – take your car to a weighbridge to make sure it isn’t exceeding its limits.
  • While at the weighbridge, weigh the van to check it’s GTM, then unhitch the van to weigh check the ATM.

It is absolutely critical that none of the recommended weights be exceeded. Not only will this greatly increase your risk of an accident, if an accident does occur, you won’t be covered by insurance. In regard to insurance, you should be looking for a company that can meet all your needs – not just one who can give you a good deal. The best way to learn, of course, is getting out there yourself and doing a towing course with your own trailer or caravan. You may even be eligible for a discount on your insurance if you do a training course!