How to improve your tow vehicle's performance

While some tow vehicles may seem perfect just as they come, if you’re towing regularly for any distance there are modifications that will improve your tow vehicle’s performance, handling, load-carrying capacity and the longevity of key components.

The automatic is the most popular transmission in Australia today, and most tow vehicles will have a self-shifter.

When towing – like most of a tow vehicle’s mechanical and some structural components – the automatic transmission comes in for additional strain. The transmission will run hotter when hauling a heavy trailer, and while many modern autos have a transmission cooler, it isn’t necessarily going to be enough for towing.

So first on your list of potential vehicle upgrades is a separate oil-to-air transmission cooler.

While manufacturers are getting better at testing vehicles in scenarios such as towing heavy loads in hot climates like ours, some don’t make it the priority you’d think they would.

Some factory set-ups have a dedicated auto fluid cooling section incorporated into the vehicle’s radiator. This design is rarely up to the job of keeping transmission fluid temperatures down when towing in hot climates. If your vehicle has this set-up, it’s likely you’ll need to invest in an aftermarket air-to-oil transmission cooler.

While some manufacturers go to the trouble of setting up a separate transmission fluid cooler, it doesn’t necessarily have the cooling capacity it should have for towing either.

There isn’t a one size fits all answer to this situation – your factory-fresh tow vehicle could have a large transmission fluid cooler that will handle anything thrown at it and still keep the fluid within acceptable range – but it’s more likely it doesn’t. Vehicles are built to a price, and there’s the risk that the transmission will fail a few years down the track because of too-high fluid temperatures during heavy-duty towing.

Ask a transmission specialist, a transmission cooler supplier or even on a vehicle-specific forum about what transmission cooling capacity is going to work for your vehicle.

Engine oil can also get excessively hot when towing and may need a separate air-to-oil cooler fitted too, although that’s uncommon these days.

Ask your vehicle’s manufacturer if an engine oil cooler is recommend. One may already be fitted as part of the manufacturer’s optional towing pack.

Standard factory suspension may not be up to the task of towing for two reasons.

New spring/shock tuning is always going to be a compromise. You can bet that most vehicle engineers were not instructed to make the suspension they were working on the best for towing trailers above everything else.

While the vehicle might offer a lush ride without a trailer behind, once on the move with a towball download ride can deteriorate. Fore-aft pitching from too-soft suspension or a jittery ride from too firm spring rates can be the result of a suspension poorly designed for towing.

Even though standard shock absorbers wear less quickly than they used to, they are still going to decrease in efficiency over time, especially when towing. They will start to provide less body control, and springs will start to sag with a lot of towing.

For any tow vehicle you plan to keep for a while, a good investment is heavy-duty springs and shocks, front and rear.

Airbag rear helper springs can improve ride and level-out the tow vehicle’s stance but should not be considered as the answer to high towball download. Air helper springs do not shift weight onto the front axle like a well set-up weight distribution hitch set-up does.

Although Gross Combined Mass (the total permitted mass of vehicle and trailer) and maximum towing capacity upgrades have become illegal in most states, you can still get a Gross Vehicle Mass (maximum vehicle weight including payload) upgrade through the likes of Lovells and Pedders.

Although you won’t be able to tow a heavier van and load up your vehicle beyond GCM, you can at least allow for often significant towball download (up to 350kg) and still have a reasonable vehicle payload. Essentially a suspension upgrade (albeit one tested and certified for you vehicle to include the GVM upgrade), you can get around a 300 to 400kg GVM increase.

You might not think a lot about your braking system because long gone are the days of frighteningly poor unassisted drum brakes all around. Even a well-adjusted disc/drum set-up can seem more than adequate (when the trailer brakes are properly set up at least).

Slotted disc brake rotors and high-performance brake pads are not just for high performance cars – they can also improve a tow vehicle’s braking consistency, especially when descending mountainous terrain where the brakes get a work-out.

Towing of course increases fuel consumption and with a long transport stage between towns in the outback, you can risk running out of fuel. An aftermarket long-range fuel tank will ease range anxiety, with manufacturers such as Long Range Automotive specialising in the field.

Modern vehicles usually don’t have engine cooling problems, but older vehicles can under the strain of towing in the heat.

Either their radiators become clogged with corrosion, or they never had adequate capacity in the first place. A larger, heavy-duty radiator with its higher cooling capacity can often be the answer.

Another option that works to keep the radiator cool in some cases is additional aftermarket electric thermo fans.

A power upgrade particularly for turbo-diesels via a chip tune can transform your tow vehicle from being a slug up the hills to something that’ll keep up with the traffic. In some cases, you’ll see better fuel economy too.

A word of caution, though: not all chip tunes or tuning boxes are created equal; they can heighten wear and damage to your vehicle’s powertrain. A chip tune can cost around $1500, so it’s not necessarily a cheap modification.

While not modifications for towing, a bullbar, driving lights, UHF radio and all-terrain tyres can certainly improve your towing experience in the bush. Wildlife strikes are common, and when towing it’s harder to take evasive action.

If you underestimate the time it takes to get to the next camping spot and end up driving after dark, driving lights can be very useful on dark country roads.

Even if you plan to stay on the bitumen, all-terrain tyres for your 4WD will allow detours on the dirt with some confidence you’ll have the additional traction and puncture-resistance of all-terrains.

A UHF radio allows you to contact oncoming drivers to ask what road conditions are like ahead and for communicating with truckies, giving them the all clear to pass you. Where there’s no mobile signal, UHF may be your lifeline to the outside world in an emergency.