Ready, steady, tow?
It isn’t as simple as hitching your caravan to your car or truck and then heading out on the road. There are a lot of legalities you need to know about different vehicles and what they’re allowed to tow. Add in the rules about towing capacity and it can get downright confusing.
That’s why we created this caravan towing guide. It will take you through all the important terms and rules you need to know to understand the towing capacity of your vehicle, so you stay safe and legal on your next road trip.
How Towing Affects Your Vehicle
When you buy or hire a caravan, you probably want the biggest and best that you can afford. But you will also need to take a close look at the dealer’s caravan weight guide. Your safety and the safety of your family depends on you choosing a caravan that your vehicle can tow safely. And this isn’t as easy as might sound.
Whether you’re towing a trailer or a caravan, it will affect your towing vehicle’s:
- Fuel consumption
Basically, the wider, longer, and heavier your trailer or caravan, the worse the effects will be. If you’re driving, this means you may have trouble turning and stopping. The road roughness, wind, and passing vehicles will have a greater effect on your driving and your control of the vehicle and trailer.
What this means is that towing a vehicle is harder than driving the vehicle alone. And you don’t want to compound that effect by towing a trailer that’s above your vehicle’s capacity. Towing above your manufacturer set limit is not only illegal, it’s also dangerous and could completely void your insurance.
Towing Capacity Guide, Australia
To understand your towing capacity, you need to understand these terms:
Kerb Weight (KW)
This is the weight of your vehicle with a full tank of petrol, oil, and a driver onboard
Tow-Ball Mass (TBM)
The proportion of the trailer’s weight that rests on the tow ball of the tow vehicle. This is important because your vehicle’s tow ball can only handle a certain amount of vertical pressure before steering and braking is affected.
The total weight you can add to the vehicle including occupants, luggage, the TBM, and any additional vehicle accessories.
Gross Vehicle Mass (GVM)
The maximum allowed weight of the vehicle, which is made up of the maximum allowed KW and payload.
Also known as “braked towing rating”, it’s set by the vehicle manufacturer and is the maximum that your vehicle can legally tow. It includes:
- Unbraked towing capacity, which applies to when you are towing a trailer without brakes
- Braked towing capacity and refers to trailers that have their own brakes
The weight of your caravan with empty water and gas tanks, but any accessories already fitted. Think of this as the weight of your caravan when it’s brand new and ready to drive out of the dealer’s lot.
Gross trailer mass (GTM)
This is the weight of the fully-loaded trailer on the axle and doesn’t include most of the trailer’s underneath.
Aggregate trailer mass (ATM)
This is the weight of the unhitched trailer on the ground, with everything loaded and is the most important when it comes to towing capacity. This number includes any bikes or extras you attach to your trailer before heading out and must not exceed your vehicle’s towing capacity.
This is the maximum towing weight for the towbar and may be different to the vehicle’s towing capacity.
Gross Combination Mass (GCM)
This is also set by the vehicle manufacturer and it’s the maximum limit your vehicle and caravan or trailer can weigh at any time. Basically, to be safe, the weight of your caravan or trailer plus the vehicle must be less than this number.
It shouldn’t be hard to find these numbers. Every caravan has a conformity plate that displays all the most essential towing-related numbers. And they should be in the paperwork and guidebook that came with your vehicle.
How to Tow Safely
This all sounds complicated, and it is. In fact, it’s probably easier to just take your fully-loaded vehicle and caravan to a weight station rather than trying to add everything together.
However, if you don’t have the time for that, then you will need to get out your caravan and vehicle numbers. An easy way to calculate how much you can tow is:
- GCM – the vehicle mass = what your trailer can weigh
This number won’t be exact, there are a lot more variables than these. But it will give you a good basis for choosing your caravan.
Towing a caravan isn’t always as easy as just hitching it up and heading out into the great outdoors. To protect your car and the safety of your family, make sure that you understand this caravan towing guide. And if you’d like someone else to take care of the hard parts of caravanning, give Caravan Partnership a call to learn how they can make it so much easier.