Payload: how much can your vehicle actually carry?

Payload is the loaded mass that your vehicle can carry before it reaches its GVM. Here is how it is worked out, what uses it up, and why the brochure figure is rarely what you get.

Facts checked

Payload in one sentence

Payload is the difference between your vehicle's gross vehicle mass (GVM) and what the vehicle weighs empty. GVM is the most the vehicle may weigh fully loaded, as set by its manufacturer (see what is GVM). Everything you add on top of the empty vehicle comes out of payload.

Queensland's Department of Transport and Main Roads (TMR) puts it the other way round: GVM is kerb weight plus tow ball mass plus payload.

The Australian Design Rules (ADR) call payload load capacity, and define it as GVM minus tare mass. "Payload" is the everyday word for the same idea. That leaves one question: which "empty" weight?

Which "empty" do you start from?

There are two different "empty" masses, both in use, and the difference between them is fuel:

The ADR measures load capacity from tare, as above. Queensland's TMR measures payload from kerb: GVM minus kerb weight, where kerb weight is the car with a full tank and no passengers, accessories or packed items.

So the gap is the fuel above 10 litres. From tare, the fuel in your tank is part of your load. From kerb, it is already counted. Neither is wrong, but check which one a figure uses. Tare vs kerb mass sets out both definitions in full.

What uses up your payload

Everything below comes out of your payload.

That last one is the one people forget. The downward load at the coupling sits on your vehicle, so it counts toward GVM and comes out of payload. Check your GVM with the caravan hitched. A heavy tow ball mass can use a large share of your payload before anyone gets in the car. See tow ball mass.

Why the brochure payload may not be yours

A brochure payload starts from one of those empty masses, defined in a particular way. Your vehicle, as you drive it, is almost always heavier:

The useful number is your GVM minus what your vehicle weighs as you drive it, accessories and fuel included. That is often well below the headline payload.

Payload is not the only limit

Staying within payload keeps you under GVM, but that is not the only limit. Your vehicle also has:

The tow ball mass from the list above matters twice here. The rear axle carries its share of the load in the vehicle plus the trailer's ball load. Keep each axle load within the vehicle's specifications. You can be within your towing limits and still overload the rear axle. This is especially common on dual-cab utes, because nearly all of their load space sits behind the rear axle. See front and rear axle limits.

A loaded car and van can each be within limits and still be over GCM together. See GCM.

Your caravan has a payload of its own

If you tow, there are two payloads, and they are separate budgets:

Packing the van does not use up the vehicle's payload, and packing the ute does not use up the van's. But one mass comes out of both: the tow ball mass. A caravan's ATM is the weight on its axles plus the weight on the tow ball, so the ball load sits inside the van's ATM. And, as above, it presses down on the vehicle, so it counts toward the vehicle's GVM too.

Caravan payloads are often smaller than people expect. RACQ's figure is that for many caravans the payload is less than 400 kg. Transport for NSW gives a worked example: a van with an ATM of 2,500 kg and a tare of 2,100 kg can carry 400 kg. Its sample packing list, from the awning and 100 litres of water to the groceries, comes to 458 kg: 58 kg over.

Like the vehicle's accessories above, after-market add-ons such as an awning, TV or extra gas bottles are not part of a caravan's tare. They count as load, and so does grey water collected on the trip. See loading your caravan.

How to find your real payload

  1. Find your GVM on the compliance or identification plate, or in the owner's manual for your exact variant. It is sometimes also on a sticker in the driver's door jamb.
  2. Weigh the vehicle at a public weighbridge with its accessories fitted and your usual fuel. That replaces the brochure's empty mass with your real starting point.
  3. Subtract that from GVM. What is left is what you can put in and on the vehicle, including the tow ball mass.
  4. Weigh it again loaded, as you travel: packed, with everyone on board and the caravan hitched. Drive onto a public weighbridge and stop before the caravan's wheels roll on. That reading is your loaded tow vehicle, and it must not exceed GVM. Allow for luggage in both the vehicle and the van, since each has its own payload.

Our guide to weighing your rig walks through the readings.

Common questions

Is payload the same as GVM minus kerb weight?

Often. As above, Queensland's TMR uses kerb weight, which includes a full tank, and the ADR uses tare mass, which includes only 10 litres of fuel. Check which one a figure uses before you compare two vehicles.

Does tow ball mass come out of my payload?

Yes. The downward load on the tow ball is carried by your vehicle, so it counts toward GVM and uses up payload. As covered above, it also loads the rear axle.

Do passengers count toward payload?

Yes. Every occupant, including the driver, is part of the load the vehicle carries toward its GVM.

Can I increase my payload?

Taking weight off the vehicle frees up payload. Raising the limit itself means raising the GVM through a certified GVM upgrade, which changes some limits but not others. See GVM upgrades before you commit to one.

Sources

Authorities

Motoring associations (advice)