Why Tow Weight Is the Most Important Spec
Ask any experienced caravanner what the most common mistake first-time buyers make, and the answer is almost always the same: getting the tow weight wrong.
Buying a caravan that is too heavy for your tow vehicle is not just inconvenient — it is dangerous. Overloaded vehicles handle poorly, take longer to stop, and put enormous strain on the engine, transmission, and brakes.
This guide explains every tow weight term in plain English so you can buy with confidence.
The Key Weight Terms
Tare Weight
The weight of the caravan as it leaves the factory — empty, with no water, gas, or personal belongings. Think of it as the "dry weight."
ATM (Aggregate Trailer Mass)
The maximum allowable weight of the caravan when fully loaded. This includes the tare weight plus everything you put in it: water, gas bottles, food, clothes, tools, and accessories.
This is the number that matters most. Your tow vehicle's maximum towing capacity must equal or exceed the caravan's ATM.
Payload (or Ball Weight Capacity)
The difference between ATM and tare weight. This is how much stuff you can actually put in the caravan.
For example:
- ATM: 2,500 kg
- Tare: 1,900 kg
- Payload: 600 kg
That 600 kg needs to cover water (100L = 100 kg), gas bottles (~18 kg each), food, clothing, bedding, tools, and every accessory you add.
Tow Ball Weight
The downward force the caravan exerts on the tow ball. This is typically 10% of the loaded caravan weight. Your tow vehicle's tow ball rating must accommodate this.
GCM (Gross Combined Mass)
The maximum combined weight of your tow vehicle (loaded with passengers and cargo) plus the caravan. This is often the limiting factor that people overlook.
How to Match a Caravan to Your Vehicle
Follow these steps:
- Check your vehicle's towing capacity in the owner's manual or on the compliance plate. This is your hard limit.
- Check the GCM rating — this may be more restrictive than the towing capacity alone.
- Target 85% of your maximum to leave a comfortable safety margin.
- Add up the payload you realistically need and ensure the caravan's payload capacity is sufficient.
Common Tow Vehicle Capacities
- Medium SUV (Toyota RAV4, Mazda CX-5): 1,500–1,800 kg
- Large SUV (Toyota Prado, Ford Everest): 2,500–3,100 kg
- Dual-cab ute (Toyota HiLux, Ford Ranger): 3,000–3,500 kg
- Large 4WD (Toyota LandCruiser 300): 3,500 kg
Common Mistakes to Avoid
1. Ignoring Payload
A caravan with a 2,000 kg ATM and 1,800 kg tare weight only gives you 200 kg of payload. That is barely enough for water and gas, let alone your belongings.
2. Forgetting About Accessories
Every accessory adds weight: solar panels, toolboxes, bike racks, generators, annex walls. These eat into your payload quickly.
3. Not Weighing Your Loaded Vehicle
Your tow vehicle has a GVM (Gross Vehicle Mass) too. A family of four with luggage in a loaded vehicle may already be close to the GVM limit before you even hitch up the caravan.
4. Trusting Manufacturer Weight Claims Blindly
Tare weights can vary from the stated figure due to factory options and production tolerances. If possible, weigh the actual caravan you plan to buy.
Use The Caravan Database to Compare Weights
Our comparison tool lets you line up caravan models side by side and compare their ATM, tare weight, and payload at a glance. Filter by tow weight on our browse page to find caravans that match your vehicle.
Getting the weight right is the foundation of safe, enjoyable caravanning. Take the time to do the maths — your safety depends on it.
