What is my Tow Capacity? Everything You Need to Know about Legal Tow Weights

Heading out for a weekend of camping or a caravanning trip is, undoubtedly, a favourite Aussie holiday.

But caravanners and trailer-towers are getting caught out at a massive rate, with their vehicles found to be either overweight or their weight distribution uneven.

As reported by the ABC in June, a police blitz found this was the case for the majority of caravanners on the road – usually because vehicle owners added accessories to their vehicle and/or caravan without considering what it would to do the load weight.

So, how can you, when towing a trailer or caravan, ensure you’re compliant?

One of the first things to do before you look at matching up your vehicle with a caravan or trailer (or vice versa!) is to check the maximum weight your vehicle can carry.

For this, you’ll have two figures:

  1. GVM (Gross Vehicle Mass) which is how much your vehicle itself weighs and can carry
  2. GCM (Gross Combination Mass) which includes not just the vehicle, but the weight of the caravan and/or trailer, and all your contents.

If your vehicle is older than 1 Jan 1992 and the manufacturer hasn’t specified these numbers for you, you can work on either 1.5 times the unloaded mass of the vehicle (if you trailer has appropriate breaks) or 750kg if the trailer isn’t fitted with brakes. 

Keep in mind these weights include everything – any passengers, accessories (towbar, bull bar, winch, roof top tents), and supplies both for your vehicle, and the caravan or trailer. 

While you can do upgrades to increase the GVM of your vehicle, keep in mind that in Queensland your GCM – your grand total – doesn’t change. Any upgrades you do will, essentially, be eating into the weight you can tow.

Unfortunately at Highfields Mechanical we have seen situations where a person has bought a car that cannot legally tow their existing caravan, as it’s GCM is too low. So, be sure to do the research before investing and pick the right car or caravan for your needs.

So, you know your towing capacity – the next step is to check if you’re within it!

 The easiest way to do this is to get your caravan and vehicle all set up and visit a public weighbridge. They’re easy to find with a quick Google!

If your load is unevenly distributed, it can be a simple process of evening it out across the vehicle and caravan or trailer. If, however, you are overweight, the next step is to see how you can bring that load down.

Perhaps you can reevaluate some of the supplies or goods you’re bringing with you. For example – are there goods you packed that you could purchase once you’ve reached your destination? Or are there accessories fitted that may not be necessary? Take a look at your options and see how you can reduce your load appropriately.

Legally, both your vehicle and trailer need to be roadworthy and the trailer must have a lit rear number plate that isn’t obscured by accessories. Towbars and couplings can’t cover the towing vehicle’s number plate or rear lights when not connected. You can also only tow one thing at a time, and people cannot ride in them.

Keep in mind that while most trailers do not need CTP insurance, your cover may be void if it doesn’t comply with legislation – including the towing capacity. There can be significant penalties in worst-case scenarios, so it’s vital your vehicle and trailer or caravan are checked.

All in all, while it can be an easy thing to overlook, it’s crucial to ensure you’re operating within the safe limits of GVM and GCM when towing.

The above information was sourced from the Queensland Government transport website, which you can visit here for more information:


If you have any questions please don’t hesitate to get in touch! Give us a call on (07) 4646 1780, or send us a message using our online booking form.