A guide to weights

When deciding which caravan or camper etc is best for you, it is a good idea to check the weights to ensure safe towing.

Overloading either the tow vehicle or what you're hauling can cause damage or even take you off the bitumen... unintentionally. The driver may be liable for fines and demerit points, it may also bring the insurance of both into question. So take a few moments to check your weights are within limits, including when fully loaded.

The weights can often be found on the compliance plate and should be checked alongside the compliance plate for the tow vehicle, which can usually be found on the towbar.

Here are some of the weight you might like to understand a bit better and consider before purchase and head off on a trip.


Tare weight (Tare)

Tare weight can be found on the caravan’s vehicle compliance plate. This is the total dry weight of the caravan as it leaves the factory including empty water tanks and gas bottles. This may or may not include aftermarket items or accessories fitted after manufacture, which may affect the Tare weight (check with the dealer or manufacturer as to whether this is the case).


Gross Trailer Mass (GTM)

The GTM is the maximum allowable weight the fully loaded caravan imposes on the ground through its axle or axles but does not include the towball mass. This rating may not be exceeded.


Aggregrate Trailer Mass (ATM)

The ATM is the total weight of the fully loaded caravan, unhitched from the tow vehicle. The ATM includes the total weight of the axle or axles plus the weight imposed on the tow ball. The ATM must not exceed the maximum towing capacity of the tow vehicle. This rating may not be exceeded.


Towball mass (TBM)

Towball mass measures the weight the caravan imposes on the tow vehicle. The maximum towball weight for the tow vehicle can generally be found on the compliance plate on the towbar. This rating may not be exceeded.


Gross Vehicle Mass (GVM)

Gross Vehicle Mass is the total weight of the fully loaded tow vehicle. It includes fuel load, passengers, cargo, aftermarket accessories, and includes the towball mass of the caravan when hitched. This rating may not be exceeded.


Gross Combination Mass (GCM)

The Gross Combination Mass is the total weight of the entire rig, encompassing the fully loaded caravan and fully loaded tow vehicle. The maximum allowable GCM is recorded in the vehicle owners manual or on the vehicle compliance plate. This rating may not be exceeded.


Braked Towing Capacity (BTC)

Braked Towing Capacity, also known as braked towing rating, is the maximum weight that your vehicle can legally tow. Vehicle manufacturers equate towing capacity to the Aggregate Trailer Mass (ATM). This rating may not be exceeded.

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