How much weight can my car carry when towing?

In days gone by, the only mass people worried about happened on Sundays. These days, if you're towing and don't kneel down and pay homage at the shrine of legal vehicle weights, you'll risk paying for your sins with a fine or worse, a crash – and no insurance payout.

While truck drivers know the consequences of taking to the road when overloaded, do we pay the same care and attention when it's time to load up the family rig, with a caravan, boat or camper in tow?

Related reading:
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You have to know what your car, SUV or ute and trailer combination is legally allowed to weigh and ensure that it isn't in excess of the vehicle's legal towing capacity.

If you read the towing section of almost any passenger vehicle's operating guide, it'll say something like this: "Your vehicle is designed primarily as a passenger carrying vehicle. Towing any type of trailer will affect the vehicle's handling, performance, braking, durability and fuel consumption."

The designers and engineers didn't get a brief saying: "Management wants a vehicle that'll tow a dirty big caravan, horse float or boat trailer, and if it happens to fit some people and their luggage inside too, that's great."

Load-bearing components like axles, suspension, tyres and the rear frame or chassis section where the towbar bolts on, are not always designed to carry heavy loads, first and foremost. Nor is the vehicle's powertrain always designed haul up to the towing capacity of 3500kg on steep inclines at full throttle on a 40-degree day...

Simply, despite the official towing capacity and what the advertisement said and showed, these vehicles won't lug the family and their luggage as well as tow a commercial airliner.

In many cases, the towing capacity claimed for a vehicle will not be realistic when the vehicle itself is packed with passengers and common commodities like accessories and recreational equipment. In technical terms, their Gross Combined Mass (GCM: the weight of both the tow vehicle and trailer combined) is too high.

Then there are those that come in under the rated GCM and when not towing anything are fine with their GVM (Gross Vehicle Mass), but when a trailer is plopped onto the towball, the extra mass pushes them over the GVM, which is also known as the Gross Vehicle Weight Rating (GVWR).

Take it to a weighbridge and get two weights. First get a mass with just the vehicle on the pad with the trailer still hitched but not being weighed. This will allow you to see whether the total weight of the vehicle is over the GVM. Then put both the vehicle and trailer on the weighbridge pad and get your rig's Gross Combined Mass (GCM).

A side benefit of this weigh-in is that you'll be able to get the trailer's axle weight (by subtracting GVM from GCM), so you can check that you're not over the towed trailer's Gross Trailer Mass (GTM) limit.

When calculating the total for both GVM and GCM consider that you must include passengers and luggage in your calculation. Four relatively light adults add 250kg. The Trucksales crew could push that closer to 400kg! Yes, it and they add up...

How do popular SUVs and utes measure up?
We've listed a number of popular SUVs and utes below to show how easy it is to exceed maximum permitted mass figures.

This is only meant to be a general guide but it underlines the importance of measuring your rig's actual weights.

Below, you'll see the kinds of items we've included in four payload scenarios. Sure, your weights are probably different (you might only have two people riding in your medium ute, not four) but you might also have a slab of beer, an off-road recovery kit and a generator in the tray, which we haven't included.

Note that we haven't double-dipped with our figures: we've included towball mass in our GVM figures, yes, but accordingly subtracted towball mass from trailer weight for GCM calculations.

So if the manufacturer claims a 3500kg towing capacity, and that's the weight of the trailer being towed (as in our examples for medium and large utes and large wagons), we've allowed 10 per cent as towball mass (350kg, which becomes part of the payload) and 3150kg as the remaining weight on its wheels (Gross Trailer Mass).

In the case of a Ford Ranger towing a 3500kg trailer, for example, we have a kerb weight of 2159kg, plus 864kg payload (adding up to 3023kg, 177kg less than GVM) plus 3150kg trailer mass (because we've already counted the 350kg TBM in payload) for a total of 6173kg (173kg more than the rated GCM).

While medium wagons and large (American) utes only represent a small section of the towing market, the towing capacity for these vehicles comes closest to reality in practice.

The worry is that the bigger-selling medium 'one-tonne' ute and large wagon segments are populated by models that can't tow what their manufacturers claim they can at their maximum passenger and payload capacity.

For the purpose of these calculations, we've come up with four relatively real-world payload scenarios. Each combines passenger and luggage/equipment in combinations that equate to the sort of use to which our test 'fleet' of vehicles would be subjected.

Payload Scenario One: 433kg
Two occupants 160kg; Tow ball mass (TBM) 150kg; Towbar and electronic brake controller (EBC) 35kg; Nudge bar and driving lights 25kg; 50-litre portable car fridge (filled with provisions) 30kg; cargo barrier 16kg; UHF radio and antenna 10kg; towing mirrors 5kg; fire extinguisher 2kg.

Payload Scenario Two: 900kg
Four occupants 250kg; TBM 350kg; Bullbar and driving lights 60kg; roof racks, tray and luggage 60kg; Towbar and EBC 35kg; 5 x off-road tyres (additional weight over road tyres) 35kg; 50-litre portable car fridge (filled) 30kg; Weight Distribution Hitch 25kg; 1 x jerry of fuel 22kg; cargo barrier 16kg; UHF radio and antenna 10kg; towing mirrors 5kg; fire extinguisher 2kg.

Payload Scenario Three: 864kg
Four occupants 250kg; TBM 350kg; bullbar and driving lights 60kg; ute hard lid 40kg; towbar and EBC 35kg; 5 x off-road tyres (additional weight over OEM tyres) 35kg; 50-litre portable car fridge (filled) 30kg; weight distribution hitch 25kg; 1 x jerry of fuel 22kg; UHF radio and antenna 10kg; towing mirrors 5kg; fire extinguisher 2kg.

Payload Scenario Four: 834kg
Four occupants 250kg; TBM 320kg; bullbar and driving lights 60kg; ute hard lid 40kg; towbar and EBC 35kg; 5 x off-road tyres (additional weight over OEM tyres) 35kg; 50-litre portable car fridge (filled) 30kg; weight distribution hitch 25kg; 1 x jerry of fuel 22kg; UHF radio and antenna 10kg; towing mirrors 5kg; fire extinguisher 2kg.

Simple mathematics shows in a number of the following cases, many common tow vehicles are close to their GVMs and/or GCMs or exceed them by only moderate amounts when towing up to the permissible towing capacity.

These are examples only. If you have any concerns, you should carefully calculate your own outfit’s loading or consult specialists if in doubt.

Hyundai Santa Fe
Payload: 433kg (Scenario 1)
Vehicle mass: 2428kg (202kg less than GVM)
Vehicle and (maximum weight) trailer combined mass: 4278kg (352kg less than GCM)

Nissan X-Trail
Payload: 433kg (Scenario 1)
Vehicle mass: 2097kg (123kg less than GVM)
Vehicle and (maximum weight) trailer combined mass: 3597kg (273kg less than GCM)

Toyota LandCruiser 79 Series d/cab
Payload: 864kg (3)
Vehicle mass: 3180kg (120kg less than GVM)
Vehicle and (max weight) trailer combined mass: 6330kg (470kg less than GCM)

Ford Ranger XLT Bi-Turbo 2.0
Payload: 864kg (3)
Vehicle mass: 3023kg (177kg less than GVM)
Vehicle and (max weight) trailer combined mass: 6173kg (173kg more than GCM)

Toyota HiLux Rugged auto
Payload: 834kg (4)
Vehicle mass: 3072kg (72kg more than GVM)
Vehicle and (max weight) trailer combined mass: 5952kg (302kg more than GCM)

Jeep Grand Cherokee
Payload: 900kg (2)
Vehicle mass: 3181kg (232kg more than GVM)
Vehicle and (max weight) trailer combined mass: 6331kg (241kg more than GCM)

Nissan Patrol Y62
Payload: 900kg (2)
Vehicle mass: 3650kg (150kg more than GVM)
Vehicle and (max weight) trailer combined mass: 6800kg (200kg less than GCM)

Toyota LandCruiser 200 Series
Payload: 900kg (2)
Vehicle mass: 3640kg (290kg more than GVM)
Vehicle and (max weight) trailer combined mass: 6790kg (60kg less than GCM)

Chevrolet Silverado 2500HD
Payload: 864kg (3)
Vehicle mass: 4380kg (111kg less than GVM)
Vehicle and (max weight) trailer combined mass: 7530kg (461kg less than GCM)

RAM 2500 Laramie
Payload: 864kg (3)
Vehicle mass: 4441kg (49kg less than GVM)
Vehicle and (max weight) trailer combined mass: 7591kg (399kg less than GCM)