Tire Pressure with different sized tires than OEM

[gordyzx9r]

Just curious how you determine what PSI to use on a vehicle when you replace the tires with a different size than what was OEM.

I've read that one "rule of thumb" is to use the max. PSI listed on the tire minus 10%.

[Steve Wood]

front tires, or rear tires?

For normal tires, I don't think size makes that much difference...3 2-34 seems to be pretty good...not too jiggly and enuf to keep from wearing the edges out and not too much to wear the center out

[Charlief1]

This has to do with contact patch. Easiest way to find a good pressure for the tire is to use a wet drive way or street. Drive through the water so that you can see the contact patch of the tire. You will need to change the tire pressure so that you get the best contact. After you do this then after about 1K miles use a tread depth guage to check how the tires are wearing. Adjust as needed.

[gordyzx9r]

front tires, or rear tires?

For normal tires, I don't think size makes that much difference...3 2-34 seems to be pretty good...not too jiggly and enuf to keep from wearing the edges out and not too much to wear the center out

The front & rear on the SUV I generally try to keep around 32 PSI.

But on my 3/4 ton I noticed the fronts were allot different than the rears.  I went up a size over OEM and recently had a leveling kit put on which required an alignment.  I think the rears were a good 25 PSI more than the fronts.

[Steve Wood]

I run 36-40 in the back of my truck and 34 in the front...

[SuperSix]

I run 34-36 in my cars. Seems to wear well.