Caravanning seems so simple that many just hop on and go. But before you do, you need to know about caravan towing weights. This collection of different tow vehicles and caravan weight measurements is a loading guide.
Some people might be towing trailers without really knowing what the standards are. They might even get away with it. But it’s best not to leave everything to chance and know exactly what you should be doing.
Ensure the safety of your passengers and others on the road by knowing caravan weight limits:
Important caravan towing parts to keep in mind
These towing tools are essential when towing your caravan. Understanding what they do and how they affect the towing of your caravan is essential when caravanning.
Tow Bar
Before any towing can be done, the vehicle must be fitted with a tow bar. This ensures the caravan will be stable during the tow making it safe for everyone. This device connects the caravan to the towing vehicle. The maximum weight of the tow bar must match the towing vehicle’s capacity.
Tow Ball
The tow ball is part of the tow bar attached to the chassis of the vehicle. It hitches the caravan to the tow vehicle. The ones commonly sold are rated 3500 kg, but some are only 2500 kg. Forgetting to check the weight of the tow ball may cause unintentional overloading.
Understanding caravan weights
Knowing the different caravan weights is vital when travelling. These weights help you determine how much you’re towing ensuring safety on the road. By understanding these weights, you can better secure the caravan or remove items that make the trailer unnecessarily heavy.
Tare Mass
This is the weight of the trailer with nothing in it or the empty caravan weight. The total tare mass of the caravan is the caravan's weight without water in tanks, gas in cylinders, accessories, or any items stored.
If there are any modifications to the caravan, the tare weight may change which could alter the maximum storage weight.
Payload
The payload refers to how much weight can be added to the caravan. This is the combined weight of fuel, water, accessories, and other items loaded into the leisure vehicle. Maximum payload is the weight limit of the load you can add to the caravan’s tare mass.
Aggregate Trailer Mass (ATM)
This is one of the most important weights to remember when towing your caravan. The Aggregate trailer mass or ATM refers to the maximum amount the trailer can weigh when it reaches its maximum payload. The ATM is the tare weight, full water tanks and gas cylinders, and everything else stored in the caravan.
The manufacturer provides your caravan’s ATM. It should not be exceeded as it may damage the caravan and tow vehicle, and it could also cause accidents while on the road.
To compute the ATM, you need to do is add the tare mass to the maximum pay load.
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ATM = Caravan Tare Mass + Maximum Payload
Gross Trailer Mass (GTM)
This is the maximum weight of the caravan supported by the axles or wheels when towing. The GTM does not include the weight it can support when hitched or with a jockey wheel when parked. This weight specifically refers to how much weight the caravan can handle when being towed.
The GTM is different from the ATM because it’s the weight carried by the tow vehicle. The manufacturer also gives the total weight for GTM.
To calculate the GTM, you must subtract the empty tow ball weight from the ATM:
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GTM = Empty Tow Ball Weight - ATM
Tow Ball Mass (TBM)
This is the weight on the tow ball from a fully loaded trailer hitched to a tow vehicle. It’s also known as the ball weight or tow ball download. Tow balls come in various weights, so check beforehand to ensure it is within the limit of your tow vehicle.
The empty tow ball weight can usually be found on the compliance plate of the caravan. You could also calculate the empty tow ball weight by subtracting the GTM from the ATM.
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Empty TBM = GTM – ATM
Summary of tow vehicle weights
Here are important tow vehicle weights you need to be aware of:
Kerb Weight
This is the weight of your vehicle without people and luggage or other accessories such as the tow bar. The kerb weight includes car fluids, oils, and a full fuel tank.
Gross Combination Mass
The maximum Gross Combination Mass is the weight of the tow vehicle with the payload and the maximum weight it can tow. Visit a public weighing bridge and check if you’re at the maximum weight capacity.
Gross Vehicle Mass (GVM)
The maximum weight indicated by the manufacturer that all the wheels in the tow vehicle can support. It includes the weights of the car, the passengers, and other things loaded in the car. When the vehicle is attached to a trailer, it includes the tow ball mass.
The formula for GVM is:
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Gross Vehicle Mass = Tow Vehicle Tare Mass + Maximum Payload
Maximum Towing Capacity
There are two types of maximum towing capacities: braked and unbraked. For braked, it refers to the highest amount of weight that your vehicle can tow when there is a trailer brake.
For unbraked, it is the highest amount of weight that your vehicle can tow when there is no trailer brake. This rating is normally lighter than the maximum braked towing capacity. Both braked and unbraked ratings are indicated by the manufacturer.
Caravan towing weight rules
The caravan’s tare mass, ATM, GTM and TBM are all indicated on caravan compliance plates. The general rule of thumb regarding the towing vehicle and caravan ratio is that the total weight of the towing vehicle (GVM) should at least be equal to the total weight of the caravan (ATM).
The Caravan Council of Australia suggests that the caravan should not be more than 77% of the tow vehicle’s weight to be safe.
Now that you know the towing weights, you can shop for a caravan that would fit your existing towing vehicle, or vice versa. This will ensure not only an enjoyable caravanning adventure for your family but also a safe one.
Let Aussie Leisure Loans help you find your new caravan. Contact us to learn more about our caravan loans or get an online quote today!
FAQ
What weight caravan can I tow?
According to the Caravan Council of Australia, the ideal caravan weight-to-tow vehicle ratio should not exceed 77% of the tow vehicle’s weight. A general rule is that the towing vehicle's total weight must be equal to the caravan's total weight.
What is ATM weight?
The aggregate trailer mass (ATM) is the total weight of a fully loaded trailer not attached to the towing weight.
Can you reduce the caravan tow ball weight?
You can reduce the caravan tow ball weight by distributing the weight inside the caravan differently. This could mean moving storage spaces or spare wheels to the rear. Although this does nothing to change the total mass, it can ease the ball's weight.
Does GVM include tow ball weight?
Yes, the general vehicle mass (GVM) includes tow ball weight as well as the weight of luggage, fuel, passengers, and the like.
What is the caravan 85% rule?
The 85% rule refers to the common advice that a caravan should weigh not over 85% of the kerb weight of the tow car.
Does tare weight include the tow ball weight?
Tare weight is how heavy a caravan is without any passengers, luggage, water, fuel, and the like. Meanwhile, the tow ball weight refers to the mass of the tow ball itself.
What is the average weight of a caravan in Australia?
Small caravans can weigh around 800 kg to 1.3 metric tonnes while large caravans can weigh at around 1.3 to 1.8 metric tonnes.
