Tow Ratings: Can you believe them?

Experts warn buyers to look beyond the marketing hype. 


Making the wrong choice when it comes to choosing a tow vehicle can be expensive and dangerous.

Having some understanding of your vehicle’s tow rating is essential, yet for many drivers these ratings are a mystery… and marketers have taken notice.

Looking at the current crop of 4X4 dual cabs on sale you could almost assume a 3500kg tow rating is now essential.

Veteran caravan industry consultant Tom Olthoff says often the advertised ratings can’t be trusted on face value.

“It’s marketers who are coming up with the tow ratings now, not engineers,” he says.

“As a buyer, you need to dig a little deeper into the claims. Even if you’re not a technically minded person, it isn’t hard to separate fact from fiction.”

Image courtesy of Hayman Reese

Image courtesy of Hayman Reese

A recent vehicle test conducted by Practical Motoring magazine looked at the advertised tow weights of all the major manufacturers and found most can only tow their advertised maximum braked trailer weight with a very light load.

If you tow right on the advertised 3500kg limit, there’s a much greater risk of overloading. Overloading can reduce vehicle performance and also damage axles, suspension, wheel bearings and tyres. In some cases overloading has lead to accidents and when this happens you could find any insurance claim is rejected.

Mitsubishi Australia, manufacturer of the popular 3100kg rated Triton tow horse actually took out full page advertisements recently explaining why the attention grabbing 3500kg rating needs further examination.

As a general rule, Mitsubishi says you need to read the fine print next to claims and crunch a few numbers to get an accurate idea of a vehicle’s capability.

The most important number to work out is your payload, that is how much weight are you carrying in addition to the vehicle itself. This is essential if you plan to tow at the vehicle’s maximum braked towing capacity as claimed in the advertising and brochures.

To work out your payload, you subtract the dry weight of your vehicle (tare or kerb mass), which is what the vehicle weighs standard from the factory, from the vehicle’s maximum weight when it’s fully loaded (GVM).

Using the Ford Ranger PX as an example, it has a GVM of 3200kg. If you subtract the tare of 2200kg, you’re left with a 1000kg payload. From that figure, you subtract the weight of passengers, accessories (bull bars, driving lights and roof racks all count here), fuel and any other added weight to determine how much payload there is remaining.

Image courtesy of Hayman Reese

Image courtesy of Hayman Reese

The other vital number to consider is the maximum towing capacity.

To find this, you need to take the Gross Vehicle Mass from the Gross Combination Mass (GCM). GCM is the maximum combined weight of your towing vehicle, the passengers and cargo in your vehicle and the weight of your trailer or caravan.

In the case of the Mitsubishi Triton 4×4 GLS, it can safely tow up to a maximum weight of 2,985kg. The Ford Ranger can safely tow up to 2,800kg, even though the Ranger’s stated tow rating is higher – 3500kg versus 3100kg.

When you add the weight of a caravan into the mix, things get interesting.

Take a Royal Flair Designer Series 198-2 for example. It has a tare of 2100kg, and an ATM of 2500kg. ATM is the manufacturer specified maximum a caravan can weigh – this includes ball weight and payload such as water, gas, food and luggage.

If we look at the Ford Ranger first, it has a GCM of 6000. Take it’s tare and the ATM of the Royal Flair away and you have a payload of 1300kg. For the Triton, which has both a lower GCM and tare than the Ford, it has a payload of 1420kg.

Despite it’s lower rating, the Triton exceeds the Ranger’s payload by 120kg.

This is just one example of how a 3500kg rating looks good on paper, but when you look a little closer, the claim will always have a few asterisks attached.

Knowing how tow weights work is a matter of safety, not only for you but for others on the road.

Link: Read the full story in Issue 17 of Time to Roam Australia