How much your ute can really tow

So you’ve been researching what ute and caravan or trailerboat you can marry up before heading off on that caravanning adventure of a lifetime or just to fulfil the dream of regular fishing weekends on a decent boat.

The top five-selling utes in Australia all have a braked towing capacity of 3500kg (except for the Mitsubishi Triton, which is capped at 3100kg), but as we’ve reported previously, that is not the full story.

Learning about ute weight facts and figures can make anyone’s eyes glaze over. It is an unfortunate but necessary fact of modern recreational towing that if you don’t get all cozy with the weighty concepts of GCM and GVM (and many more), you can run into trouble.

The reason it’s so important not simply load up your ute with whatever you want and tow whatever you like is safety and the legislation surrounding it.

Overload your ute and/or lug a trailer that’s too heavy for it and you risk the rig being so heavy and potentially unstable that something breaks and you crash.

It may also involve you copping a fine and accruing license demerit points, or even facing a manslaughter charge if it all goes terribly wrong.

This wasn’t (and mostly still isn’t) really policed much, except in commercial trucking, because recreational towing weights and the number of people doing it have increased dramatically only relatively recently.

Engineers at car-makers test their utes during development to determine what weight is safe to carry in and on a vehicle without breaking it, blowing it up or making it unstable.

That maximum permitted weight is called Gross Vehicle Mass (GVM). If you subtract the kerb mass of the vehicle (generally speaking, the weight of the vehicle as it stands at the end of the assembly line) from GVM, you have what is called payload.

Payload is the maximum weight of people, accessories and cargo – including everything down to your sunnies – that you can add into the ute.

The definition of kerb weight and how it is measured differs. According to the DIN standard it is the mass of the vehicle in running order unoccupied and unladen but with all standard equipment and fluid reservoirs filled to nominal capacity, including a 90 per cent full tank of fuel. EU kerb weight figures are 75kg higher to account for the driver.

If you go and fit that you-beaut steel bullbar, canopy, spotties and long-range fuel tank, then you are taking up some of your available payload with this gear.

Original Equipment Manufacturer (OEM) engineers also test to see how much trailer weight a ute can tow without breaking off its towbar or making the ute spear off the road due to instability.

That, of course, is called maximum towing capacity. But another weight you need to know is Tow Ball Mass (TBM), which is the maximum safe weight the manufacturer has decided the trailer coupling can push down on the towball of the vehicle without risking breaking the towbar or the rear axle.

Finally, there’s another towing weight that the engineers decide on, which is the maximum safe weight the ute and trailer can weigh combined, without risking the ute overheating, destroying its transmission, cooking its brakes or being too unstable (among other things). That weight is called Gross Combined Mass (GCM).

These manufacturer-set weights are not just so you can’t make a warranty claim if you exceed them; they become a legal safety requirement once you hit the road. You, as the vehicle operator, can’t allow your rig to weigh any more than these maximum weights without breaking the law. That can be a lot easier said than done with these utes, as many have discovered.

All of the utes listed here are top-spec dual-cab 4x4 variants in their respective ranges (specified with an automatic transmission, where not standard), excluding off-road focussed models like the Ford Ranger Raptor and Toyota HiLux Rugged X, because that is the most popular body style, drivetrain and trim level for recreational towing.

In practice, towball weight becomes vehicle payload once you’ve hitched up (because the front part of the trailer’s weight is pushing down on the tow vehicle, not on the trailer’s wheels) but that’s not how GCM is calculated, ideally.

A manufacturer cannot possibly know what each operator’s individual towball mass is going to be, so the best ones have a GCM that equals the total of GVM and maximum towing capacity.

That would mean a zero TBM of course, which doesn’t happen, but at least it allows a safety margin if your TBM is less than 10 per cent (which can happen, especially for trailerboats).

All utes here fall short of that ideal. That is, all would exceed their GCM if you add GVM and full towing capacity together.

For starters, you’re on the backfoot simply by towing a trailer. Trailer nose weight, or towball mass, becomes part of your ute’s payload, because the trailer weight over the coupling is not being supported by the trailer wheels. Instead, it is being supported by the ute’s back wheels.

That means you have to subtract this towball mass from the ute’s maximum payload to see how much weight you’re left with and can add to the ute.

And when towing a 3500kg trailer, that means you have as much as 350kg you can’t put in or on your vehicle, because your trailer is already using that amount of payload up just by sitting on the towball.

However, as we’ll explain, if you’re towing a heavy enough trailer, you won’t have to worry about TBM eating into your ute’s payload; it’s GCM you have to worry about.

Because everyone’s towing weights and payload are different, there’s no definite towing figures that work for everybody (except the legal maximums, of course). There are too many variables.

The only way you will really ever know if your rig is legal is to get it weighed at a public weigh bridge or by a private weigh operator.

That doesn’t mean you have to go into this blind. There are two ways to estimate weights before you buy: realistic towing capacity, or payload remaining when towing at maximum capacity.

Realistic towing capacity is simply calculated by taking GVM away from GCM. That leaves you the total legal trailer towing weight that the vehicle can tow, regardless of where that weight is shifted (that is, even though approximately 10 per cent of that becomes vehicle payload via towball download).

Those with a lot of towing experience will argue that if you start with a trailer that weighs about the same as the tow vehicle (or better still, less than the tow vehicle), you are well on your way to having a stable towing rig.

The heavier the trailer is than the tow vehicle, the harder it is for the tow vehicle to stop being literally pushed around by the trailer at speed.

But what happens if you must tow at or close to the maximum legal ratings of these popular utes? There is nothing stopping you doing that, but you won’t be able to carry as much in the ute as a result. We’ve shown in the table below just how little you can carry in your ute if you have a heavy trailer behind.

The ‘realistic payload’ of all utes have their towball download weight (which is estimated as 10 per cent of trailer weight) subtracted.

For example, the Ford Ranger’s maximum real towing capacity is 2800kg (GCM 6000kg minus GVM 3200kg) and towball download is therefore estimated at 280kg. Its real payload is therefore 3200kg (GVM) minus 2246kg (kerb weight) equals 954kg of total payload minus 280kg (towball download), so 674kg.

The least tow-capable ute using this formula is the Toyota HiLux Rogue, with just 2800kg of trailer and 539kg of payload. The most weight you can play with for trailer and payload combined is the Nissan Navara ST-X, with a 2760kg towing capacity and 748kg of payload.

If you want to tow right at the limit available, most utes have a problem with exceeding GCM. You simply can’t tow a heavy trailer and carry heavy stuff at the same time in most of these utes.

The HiLux Rogue (with a 3500kg trailer) would have just 119kg of usable payload remaining. That is barely enough to for a couple to sit in the ute on holidays, assuming they’ve severely restricted their diet in the months prior to the trip.

Cast an eye over the heavier, off-road kitted HiLux Rugged X specs and you’d have to surmise that Toyota isn’t expecting owners to tow anything heavy. The Rugged X weighs 85kg more than the Rogue but has identical GVM/GCM limits. That means the Rugged X has just 34kg of remaining payload when towing 3500kg without exceeding its GCM.

The Mitsubishi Triton has the most remaining payload with its 3100kg maximum-permitted trailer, at 590kg. However, as the Triton is the only ute here where a towbar is optional (and therefore not part of kerb weight), you’ll also have to allow around 40kg of available payload for a towbar kit.

The Triton is also the only ute here that can use all of its 900kg payload (310kg estimated TBM plus 590kg of usable remaining payload) when towing at its maximum 3100kg, without exceeding its GCM. The Nissan Navara has the most amount of payload left over that it cannot use without exceeding GCM, with 390kg remaining.

The upshot of all this is simply this: you cannot realistically tow a heavy trailer and carry a heavy load at the same time in any of Australia’s most popular dual-cab 4x4 utes. They are all a compromise – clearly some more than others.