a64pilot

Any general rules or ideas for proper air pressure for highway use for say 33x11’s, 35x12.5” etc. for even wear?
Off road everyone has their own ideas usually, but what should we run on pavement? I have 295/70 basically 33x11.5’s on stock rims and am starting at 32 PSI, is that about right for average 2 dr?

Jay2013jk

Check out this video and more on Chalk Test for PSI...

icrashbikes

Chalk test it. It's really the only way to know since there are so many variables. Draw a thick chalk line across the tread from sidewall to sidewall. Go for a drive and check the wear pattern. If you have a band of chalk worn off in the middle, pressure is too high. A nice even wear across the tread is what you're shooting for. There are plenty of photos online for reference. The ideal pressure may change with some mods too. A full belly of armor, some sliders, and steel bumpers will definitely make a significant difference in weight and tire pressure required for even wear.

Edit: Jay you beat me to it!

a64pilot

Thanks, makes sense. Tires I have have a more rounded profile than a flat one so not sure how much that changes anything, one of the reasons I chose them.
Back in my racing days we would take a couple of laps then measure temp across the tire looking for an even temp, similar concept to the chalk I guess.
Bushwheels on airplanes we just aired them down until they had a little belly for rough ground and aired up until they lifted the first line toward the side for pavement.
I left the tire store and when I got home they were 45 PSI which of course was way wrong you could feel every knobbie at slow speed.

I’ll do the chalk test but it’s going to be a week I think as Fl is looking at 5 straight days of rain.

Thanks for the link and answer.