Best PSI for 235/75/15 tires?

[RTStork]

I have Goodyear Wrangler RT/S and Ford says 26-28 psi and the tire says Max 44 psi. Now I know that 26-28 is way too low for hwy use. I would believe that the heat would wear them out quicker, not to mention it would probably hurt gas mileage. I also believe that 44 psi seems too high. I'm running 35 psi right now and I was wondering what psi would give me the most even wear and most treadlife? Thanks!

 

[ok89]

What is says on the tire is the max. meaning that it shouldnt be run at that pressure. That pressure should only exist in the tire when it is really really hot. I believe Gjarrett(sp) did a great write-up on determining the perfect tire pressure for new tires.

 

[aldive]

I run 40 psig in mine.

 

[2001ExpSport]

Running anything higher than 30 psi is going to be the too high. I have never run anything over 30psi. If want to get real technical you can run 28 in the rear and 30 in front.

 

[RTStork]

Thanks! So, I suppose that 30 psi has given you the most even wear? They had 30 psi when I bought the Explorer, but they seemed to bulge and they looked a little flat.

 

[98 exploder]

I have pirellis, a little diff't than wrangler but I keep mine around 32-35 psi and I find that to give plenty of grip and works in highway driving well.

98 explorer XLT V8 AWD
S&B high flow
edelbrock IAS shocks/Explorer X sway bars
2 10's and pioneers all around

 

[2001ExpSport]

Originally posted by 98 exploder
I have pirellis, a little diff't than wrangler but I keep mine around 32-35 psi and I find that to give plenty of grip and works in highway driving well.

98 explorer XLT V8 AWD
S&B high flow
edelbrock IAS shocks/Explorer X sway bars
2 10's and pioneers all around

The range is about 28 to 35. For a standard duty tire on your Ex, 30 psi will be prefect.

 

[2001ExpSport]

Originally posted by 98 exploder
I have pirellis, a little diff't than wrangler but I keep mine around 32-35 psi and I find that to give plenty of grip and works in highway driving well.

98 explorer XLT V8 AWD
S&B high flow
edelbrock IAS shocks/Explorer X sway bars
2 10's and pioneers all around

The range is about 28 to 35. For a standard duty tire on your Ex, 30 psi will be prefect.

I run 33" Swampers and to get the best and even wear I run 22 psi in the rear and 25 psi up front. I know a guy who runs less than 20 all the time. It depends on the tire. Again, for you, 30 psi is best.

In 1958 the DeSoto line came with the option to get Goodyear's 11x14 luxury tire which required 14-17 psi. How's that for low?

 

[GJarrett]

Do a search for "chalk" to find links to the chalk test. Here's one of the later threads asking your same question that links to earlier instructions on how to do it:

Dead Link Removed

As long as your tires are still fairly new (with a level tread) the chalk test will tell you exactly what the perfect PSI is to keep your tires at for your particular vehicle and tire size/brand. 32 PSI give or take a couple of pounds will probably be fairly dang close to what yours will test out to be.

This keeps coming up every few months or so. I think I'll add the chalk test to my article on the "Gerald's Truck" thread in my sig line so everyone can have a central place to find the info.