Street PSI

[LiquidOps]

Just a curious question. I've heard rumors and different theories on what it should be set at.

92XJ Sport 2door.

3" lift 31x15x10.5 AT's

What do you guys have your PSI set at for just everyday driving.

The most load I ever have in it is my Mt. Bike in the back.

 

[xj92]

3.5" lift with 31x10.5's, never carry much of a load either. I run mine at 32psi on the street.

 

[Scott Mac]

Just a curious question. I've heard rumors and different theories on what it should be set at.

92XJ Sport 2door.

3" lift 31x15x10.5 AT's

What do you guys have your PSI set at for just everyday driving.

The most load I ever have in it is my Mt. Bike in the back.

Set it to the point where you're comfortable with the ride, handling and gas milage. I run my 33s at 35 psi on the street.

 

[LBEXJ]

I run 32 x 11.5 BFG MT @ 22psi. I know that sounds low, but my contact patch is flat so I get even wear ... and I like a smoother ride. Easier on this scawny ass of mine

 

[choad]

I run 31x10.50 BFG AT's at 32psi in front and 28psi in rear. Never rotated and they still look flat after 2+years.

 

[choad]

I run 31x10.50 BFG AT's at 32psi in front and 28psi in rear. Never rotated and they still look flat after 2+years.

Let me rephrase that. They haven't been flat for 2+ years. There is lot's of air in there. What I meant to say was the treadwear has been nice and even.

 

[LBEXJ]

:laugh3: ... thanks Choad. Was kinda wondering about those "flat tires" ..... Sounds like I am running the flat tires @ 22psi. I drive lots of rough paved backroads, gravel, and secondary highways here where I live. At 30+ psi it was beatin' the heck out of everything.

Somewhere, I read an article about how to check your contact patch using chalk. Has anyone else seen this? It was kinda interesting.

Les

 

[choad]

I'm with you on rough roads. I hate washboard! I usually air down to 20psi before I hit a dirt road heading to a trail.

I've used chalk in the past. Just run a line 1" wide or so across the tread. Go for a drive around the block and see how it's wearing.

 

[azxjman]

so I guess I ride low at 15 p.s.i. all the time

 

[Phil]

I aired down my tires (35" MT/Rs, longbed MJ) until the edge of the tread was flat on the ground, or just a very little off of the ground. I slid a peice of paper under the tire, and aired down until the tire was just holding the paper tight. I ended up with ~26psi front and ~17 psi rear. The rear sounds like it is low, but I think the rear of an MJ does not have a lot of weight, compared to an XJ. Also, as tire size increases, the pressure required to support a given load should decrease. Of course, when I get my spooled 44 rear in, I'll probably air back up towards max pressure in the rear.

 

[h.curtis]

I found running 28 pounds was good wear after over 70K worth of miles on 31's for the street. I ran more and found I was wearing the center of the tire too much. My XJ has no after market bumpers or anything, so it is pretty much stock weight. I run 31 pounds with my 33's now and find they needed a little more air to wear even. If you are stock weight I think 32 pounds is too much, but I am running BFG KO's and that may make a difference as well. If you are running a tire with a weaker sidewall, you may need more pressure.

Enjoy,
Curt

 

[MojaveDXJ]

The only way I can get a flat footprint on my 31x10.5x15 BFG All-Terrain T/A ko's is to run them at 20psi. Any more than that and the sides don't even touch the ground on a flat surface.