One of the most common questions we see on the forum about off-roading is what air pressure on your tyres you need on the trail. The answer to this question is not as simple as you think.

It depends on various factors such as vehicle weight, terrain, tyre width, sidewall height, tyre construction and sidewall height. In this blog post, we are going to discuss the different factors to determine the best tyre pressure to run on the trail.

4 Factors To Determine Air Pressure On The Trail

Beadlock Rims

When most people hear about reducing the air pressure on your Cheap Car Tyres, the first thought in their minds is bead lock wheels. If you are running single-digit air pressure on the trail, then bead locks are for you.

This usually only locks the outer bead, but some wheels keep both the inner and outer bead in place. There are drawbacks to bead locks, though they are not often talked about.

These bead lock rims are more expensive and heavier than regular wheels and all those locks need additional maintenance. You can still reduce the air pressure of your tyres on the trail, even if you do not have bead locks.

Rim Width Relative To Tyre Width

If your tyre has more sidewalls, you have more margin as to how wide of a wheel you mount it on. For example, if you choose the LT245/70R17 Nitto Terra Grappler G2 has a rim width of 6.5-8 inches which is only ½ inch in the range. But the same tyre of a 37×12.50R17LT has a rim width of 8-10.5 inches, which is a 2 ½ inch range.

That is because the sidewall on the 37 is ten inches tall and the sidewall on the 245 is only 6 ½ inches tall. We make a mistake on the narrow side when choosing wheels as this increases the pressure in the bead air and gives lower air pressure to be moved on the trail without losing the bead.

The deal is that at normal inflation pressure on the street, a tyre mounted on a narrow wheel can wear out at the centre of the tread rapidly.

There are only five sizes available with one load rating, so if you want to drive on, for example, a 35-inch tall Pro Comp Xtreme MT2, you end up with a load range E tyre capable of carrying 3,195 pounds each at maximum inflation.

These would require you to reduce the air pressure further on a relatively light Toyota or Ford to get the same contact patch as you would get on a full-size SUV at a higher inflation rate.

Tyre Construction And Vehicle Weight

As you know, not all tyres are created equal. Tyres which have higher load ratings are capable of carrying heavy loads, but they also have stiffer construction.

For example, BFGoodrich tyres offer the All-Terrain KO2 at a 265/70R17 rated to carry 2470 pounds at 50 psi and also the same size to carry 3195 pounds at 80 psi. The higher-rated tyres also have more weight, usually a few pounds heavier.

Often, the tyre you are looking for is only available in one load range for a given size, so if you want to drive on 37-inch Toyo Open Country M/Ts on your Suzuki Samurai or your Ford Super Duty, they will be the same tyre. The chances of losing a bead on the Ford Super Duty are higher than the Suzuki Samurai.

Usually, a tyre with a lower load rating will have a more flexible sidewall that easily runs in the terrain without the risk of the tyre coming off the rim. The drawback is that those flexible sidewalls are also more prone to the risk of a puncture, especially when rock crawls at low inflation.

Terrain

Terrain is important when you determine the air pressure in your vehicle. In soft sand and deep snow, you have to run as low as 2 psi for the wide surface to reduce the contact pressure and float on top of the soft surface by spreading the weight of the vehicle.

In these situations, you need to require bead locks, especially if you are driving at high speed and driving through the terrain which can peel the tyre off the rim.

When driving on rocks, we recommend reducing the air pressure to around 12 psi on vehicle tyres like a 4,700-pound Jeep. This is enough to get better traction and improve the driving experience while not being so low too prone to punctures where the tyre gets cut by the rim when it bumps into a large object.

Some good brands offer air compressors like Vi-air that have complete air systems for a variety of applications for filling up air in Dunlop Tyres UK.

The air tank will be placed inside the frame rail of your vehicle. You can let the tank pressurise to a different psi and then quickly transfer that air to a tyre. This is a useful system for airing up, and it also helps when you have a tyre debate where quick air is necessary.