Postby mar1 » Thu Nov 03, 2011 1:50 am
people usually get the concept of tire pressure wrong when it comes to offroading.
first of all, know your tires. every tire has a different rigidity, and different deflation shape. example, you will need to deflate a rigid tire like a swamper much more than you would a soft tire like the Geolandar.
second, the weight of ur car plays a huge role in how much you need to deflate. the heavier the car, the less you need to deflate since the weight will compress the tyre more. I've known Jeep owners that completely remove the valve on mud (0 PSI) swampers and the tire still holds up. can't really do that in a pathfinder.
third, the terrain you will drive on. if your climbing rocks, you may need a bit more pressure than sand, so the tire doesn't pop out on on a jagged edge.
in short, keep deflating your tire till you see the sidewall start to bulge, and you will notice the bottom area of the tire now covers more ground. THEN measure the tire pressure and deflate the rest.
Cooper STT you can probly go down to 4-5 PSI
Michelin LTX you shouldnt go down less than 10-11 PSI