When off-roading, one of the most effective ways to improve your performance on the trails is by changing your tire pressure. Since the tires are the point of contact between your rig and the surface, it makes sense that modifying them in some way would have an impact on the vehicle’s off-roading performance. In most off-highway situations, this means reducing your tire pressure.
You might have the most souped-up custom-built truck ever but if you don’t master how to air down your tires when driving over off-road surfaces, you’ll always perform badly on those trails.
Deflating your tires in off-roading situations has a huge effect on the vehicle for the following reasons:
It helps increase traction.
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When driving on smooth, slippery surfaces such as snow, sand or mud, your tires need all the traction they can get to prevent them from getting bogged down. Airing down your tires increases their footprint i.e. it increases the surface area of rubber that’s in direct contact with the ground. This in turn distributes the vehicle’s weight more evenly, preventing it from sinking and giving it a better grip on the ground.
It improves ride comfort.
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Driving over rough terrain is often an uncomfortable experience as you continuously get jostled around. Decreasing the tire pressure improves ride comfort by softening the tire, allowing it to absorb more of the vibrations that would’ve been transferred through the suspension to you and other passengers.
It protects the tires from punctures.
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Airing down also allows the tire to shape more comfortably around obstacles on the trail. Instead of presenting more resistance to hard, sharp objects, aired down tires conform to the terrain, decreasing the chance of getting a puncture.
It’s also better for the environment.
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Another advantage of reduced tire pressure when going off-road is that this allows your vehicle to sit on the ground surface rather than digging into it. This way, your four-wheeler won’t damage the tracks or trail surface, helping to keep them intact.
Re-inflating your tires once you’re back on the highway is just as important as airing down when going off-road. Driving at highway speeds on deflated tires is dangerous because the low pressure coupled with the flexing in the rubber leads to a gradual heat build-up in the sidewalls. This eventually weakens the rubber causing tire blow-outs that put you and your rig in danger. Additionally, making high speed turns on tires with reduced pressure can cause them to blow a bead or come off from the wheel rim. This increases the chance of your vehicle rolling over.
Overall, maintaining the proper tire pressure both on and off-road improves your four-wheeler’s performance, increases your fuel economy, lessens the wear on the tires, and also gives you the correct traction to help prevent accidents.
Factors to Consider when selecting the proper Off-Roading PSI
There are several things to consider when it comes to choosing the right tire pressure to use in off-roading situations.
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Wheel Size vs. Tire Size
To determine the right tire pressure, you have to consider how much rubber you have between the rim and the ground surface. The lower your tire profile, the less you’ll be able to reduce the pressure without risking some damage to the tires. For instance, if you have a 15” wheel and 35”-37” tires, you can probably go down to 10PSI but if running 18” wheels then 20 PSI is as low as you can go. Getting the tire aspect ratio wrong could damage the interior of the tire if it gets pinched between a hard surface like a rock and the rim.
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Sidewall stiffness
Stiffer tire sidewalls provide the right support to prevent the tire from flattening out. Unfortunately, stiffer sidewalls aren’t an advantage when off-roading due to their reduced flexibility. Deflating the tires solves this problem by decreasing sidewall flexibility, allowing tires to better conform to obstacles.
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Your driving speed
Driving fast on aired down tires results in constant flexing. This in turn leads to a building up of heat in the tires resulting in eventual damage. This kind of damage usually goes unnoticed until something more serious like a blow-up happens. Another disadvantage of fast driving on deflated tires is that it can cause the tires to detach from the rim. It’s therefore important to adjust your driving speed to the tire pressure and a good rule of thumb to follow is- the lower the tire pressure, the slower you should go.
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The trail surface
Before airing down your tires, you also have to consider the surface you’ll be driving on. How smooth or rugged is the terrain and how accommodating is it? For instance, if you’re doing some dune running, you can go down to a much lower PSI. This is because the sand deforms to accept the tire footprint without offering much resistance. The reverse is true if driving on a hard surface- tarmac or gravel roads are less forgiving so you’d do best to use a medium-range PSI when driving over these surfaces.
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The aggressiveness of your steer
Another thing to consider is whether or not you’ll be taking fast turns with your ride. If you’re going to be driving on sand, for instance, you could go all the way down to 10 PSI as long as you stick to a straight line. However, doing tight high-speed maneuvers on aired down tires increases the risk of blowing a bead. You could of course use invest in beadlock wheels to avoid this but then the risk of damaging the tire still remains.
There’s no one-size-fits-all approach to determining how low to go when airing down tires. You just have to consider all the factors above and experiment with different PSI settings to find out what works for you and your rig.
If you’re not sure about the lowest PSI you can comfortably run your tires on, or are just looking to purchase some tire deflators or an air compressor, feel free to come speak to us at either of the Dixie 4 Wheel Drive auto shops in Moab or St. George.
