I just want to get this out of the way. Yes, I do realize that people have beat this poor sad horse to death, but bear with me.


Now, currently I have 33x12.5's, but I am downsizing to 31x10.5 r15's on my '87 4Runner. Anyway, I am wondering what the MINIMUM pressure is that I can run for trail use (Without Beadlocks). I will be running ~35 PSI for on-road use, but how much should I air down for crawling without breaking a bead?

Thanks,
Nathan

 

It really depends on how wide your rims are. For example, a 33x12.5" tire can be aired down more on a 8" wide rim than on a 10" wide rim.

 

Youll need different pressure for different suitations/ driving skills. But I would say, with a non beadlocked radial, keep it above 15psi. On my pickup with 35s on a 8" wide rim I would to run 15 in the front and 10 in the rear. Only ever lost front beads on tight down hill turns...

Carry some tire spoons and learn how to put a tire on by hand.. May come in useful!

 

I have run my 31/10.50/15's as low as 8 PSI on 8 inch wide rims on my pickup.


Depended on whether front or rear and how much weight I had in bed. AND if just on easy trail or hardcore rocks. Different weight and conditions require different pressures.


Experiment and see what works best for you and your terrain. When I was down to 8 PSI I never lost a bead but it did feel like I was riding on balloons. Kind of squishy but way smoother than full pressure and tons of traction.

 

Ok, thanks guys. I have 15x8 in. rims, and I have never been wheeling before, so I will keep them at ~15 PSI until I get the hang of it.