MORE TRACTION GUARANTEED
Brought to you by Drivetech 4x4, this article was published by Australian 4WD Action Magazine (Issue 260 - 2016). Words by Steve Collins. Photography by Dean Johnson & Drivetech 4x4. To download the full article, CLICK HERE.
Expert tips for setting the perfect tyre pressure across every terrain
Getting your tyre pressures right when you’re heading off-road costs nothing, yet gains so much. Dropping out a few PSI allows the tyre to mould around an obstacle, improving grip and reducing the chance of sustaining damage. But because every 4WD, tyre and driver are different, there is no one-size-fits-all
solution when it comes to tyre pressures. On top of that, we all think we’re choosing the right tyre pressure - but how many of us have done the testing to find out for sure?
With that in mind, we caught up with Ben Lavis, Drivetech 4x4 Business Manager to get his expert tips for finding the perfect tyre pressure for your 4WD, across every terrain.
BEACH & SAND
“It’s important to remember that every 4WD and tyre is different,” says Ben Lavis, “So the trick here is to experiment to find the best results for your 4WD.
“In the sand, start by dropping your tyres down to about 16psi. If you start digging down, drop a few more pounds out. But remember, once your tyre pressures are that low, you need to drop your speed and avoid sharp turns to suit, or you could peel your tyre right off the rim. Getting the pressure right is a cinch with the Drivetech 4x4 Tyre Deflator, as its all-in-one mechanism allows you to quickly drop your psi and accurately check your pressure in one simple movement.
“When it comes to corrugated high-speed dirt tracks,” says Ben. “Start around the 28psi mark and keep your speed under 80km/h to help cushion the ride. You do need to be careful not to go too low, or travel too fast, or there’s a good chance the tyre will overheat.”
“18-20psi is usually a good pressure to start with for easy-going dirt tracks like fire trails,” says Ben. “Caution is required though, because if the tyre or sidewall nudges a rut or rock, you might end up snagging the sidewall or wedging dirt in the bead. There’s also the very real possibility of puncturing a tyre when you’re travelling at speed. That’s why the Drivetech 4x4 Air Compressor Kit comes with a puncture repair kit - so you’ve got all the gear you need to
fix the tyre and pump the psi back up in the one bag.”
LOW-RANGE ROCK CRAWLING
“I’d recommend experimenting between 16psi and 22psi while keeping a close eye on the tyre’s sidewall. If you’re running low profile tyres you are better sticking to the higher end of the psi range to avoid damaging your rims,” says Ben. “One downside to low tyre pressures is a slight loss of ground clearance. To give you an example, for every 10psi you drop out of a 35in tyre, you’re likely to lose 10mm in diff clearance.”
“Mud can be difficult to get right because each mud hole is different from the next,” says Ben. “Whilst some suggest a slightly higher tyre pressure of around 22psi as it allows the tyre to slice down through the sloppy top layer and actually bite down into the harder crust beneath, others believe the bigger your tyre footprint, the more grip you’ll have and so they aim for a lower pressure of around 14psi. That’s why having both an air compressor and tyre
deflator on hand is so important, and exactly why we’ve got both in the Drivetech 4x4 Air Compressor Kit.”
“Depending on the surface under the water,” says Ben. “Aim between 18-22psi as starting pressures when tackling water. It’s important to remember that the more air that remains in your tyres, the more buoyancy your 4WD has, and so the greater the chance of it slipping off course in flowing water. And like rock driving, the lower you go with your pressures, the less diff clearance you’ll have, meaning you’re more likely to get caught up on a stray boulder.”
THE 4PSI RULE
“The 4psi rule can be used across any vehicle, on any terrain, to determine the best pressure for your tyres and the speed you are travelling,” says Ben.
“Starting with cold tyres, set the pressures you think best suits the terrain and speed. Go for a drive for about an hour to allow the tyres to warm up, and then pull o ver and check the pressures again.
“If they have gone up by more than 4psi, then the starting pressure was too low and you’ll need to add a couple of pound into each tyre next time. If they have gone up by less than 4psi, then your starting pressures were too high and you could drop a couple of pound out.
“The only thing to keep in mind is that this doesn’t take into account the possibility of rolling the tyre off the rim, so
your safest bet is to go no lower than 14psi, unless you’re really in trouble.”
A QUALITY AIR COMPRESSOR MAKES ALL THE DIFFERENCE
“It’s when you don’t have the right gear on hand that things can go pear shaped when it comes to your tyres,” Ben says. “That’s why carrying a tyre deflator, air compressor and puncture repair kit at all times is so important - it means that whatever terrain you’re driving, you have the means to protect your tyres, and if need be repair them so you make it out safely. That’s why we’ve designed the Drivetech 4x4 Air Compressor Kit to include all of these things. From the
incredibly quick 180L/min air compressor to the quick deflator that’ll have your tyres at the right pressure in no time, and the tyre repair kit that comes complete with everything you need to repair a puncture in the bush, this kit has you covered. All items are available separately as well.”
Drivetech 4x4 are a leading developer and distributor of quality 4WD replacement parts and accessories across Australia and New Zealand, with a huge range of parts for most popular 4WDs. To find out more or find the details of your nearest stockist CLICK HERE