By Jon Maib
Let's talk about tire pressure for off-road. With many new people coming into the off-road community with the popularity of the Jeep JKU, most are unaware where to begin for off-road tire pressure. More and more people are putting bead lock rims on their Jeeps simply because they look cool. I've talked with several guys about the air pressure they run and most seem to be running somewhere between 12-15lbs which completely defeats the purpose of bead locks. I've been wheelin' for over 15 years now on tires from 31" – 35" with no bead locks and have never popped a bead while running 8-10lbs of air in them. I've been called old school in my wheeling habits, and that may be true, but experience breeds confidence.

I struggle seeing a 37+ inch tires with bead locks on the trail with no tire bulge due to high tire pressure. I know a lot of people don't like to air down too much simply because they then have to find the way to air back up. These days however, a lot of our off-road parks are providing air supplies to get you taken care of after your day of wheelin'.

A good way to determine what pressure works for you is by just experimenting on how much you can lower your tire pressure in order to find that sweet spot. In doing this, there is the possibility for you to unseat your bead while wheelin' (if you are not running bead locks) but don't be too afraid of that. Seating a bead is not as difficult as you may think and if worse comes to worse, you should have a spare tire you can use. So, a good starting point for most tires without bead locks is somewhere in the range 8-12lbs. On my 35" BFG's I will run 10lbs up front and 8lbs in the rear (and I have never popped a bead). Running a little higher in the front will ensure that the bead won't pop off when you are making hard turns. If you are running bead locks, you really should be running single digits (somewhere between 5-8lbs for starters).

Tire pressure can vary depending on your tire size, rim size, lift size and the terrain. You will just have to figure out what works best for your rigs setup. Airing down gives you a larger foot print that allows for better traction and better wheelin'. I have seen a vehicle on 40" tires struggle up an obstacle because they just didn't use the right air pressure where a vehicle with smaller tires and proper air pressure walked right up the same obstacle. Below you can see the benefits of lower air pressure in both a 35" tires without bead locks and a 37" with bead locks. See how the tires conform to the rocks and give you better traction.

35x12.50 R15 BFG KM2's with C Load range at 5 lbs

37x12.50 R17 Cooper Discoverer with D Load range at 5 lbs

I purposely popped a bead off my tire to clean out some rocks that had become lodged between the bead and the tire from running 8lbs on our last trip. Reseating the bead just takes air pressure, so if you have onboard air, you can fix this sort of thing right on the trail. However, if you pop both inner and outer beads, your day just got really difficult and may just be easier to throw the spare on and keep going. There are many ways to get a tire back on the rim, which I won't go into on this article, but it can be done.

While airing down will provide maximum traction off-road, the one drawback to airing down can be clearance. With 35's at 30lbs of pressure, my Jeep sits at 11 1/2 inches of clearance between the ground and the pumpkin. Airing down to 20lbs we loose a half inch of clearance. Airing down to our standard 8-10lbs, I have lost a full 2 inches of clearance between the ground and the pumpkin. This is why a lot of people are going to larger tires these days as it helps maintain higher ground clearance. On our Project Vulture, which is sitting on 285x65 R18 A/T's, the clearance becomes an important measurement because 8lbs of pressure in these only give us ____" of clearance between the ground and the pumpkin.

So don't be afraid of airing down a bit more than you think is possible. Most tires will retain the bead at 10 lbs of pressure and if you are running bead locks, don't be afraid of those low single digits!

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