Generally, for most off road vehicles 15-20 PSI is a good starting point compared to 35 PSI +/- found on most stock tires.
For very soft sand – such as dune running – 10 PSI may be optimal but at tire pressures that low, you are risking the tire coming off the bead.
Is 38 psi too high?
Higher pressure generally is not dangerous, as long as you stay well below the “maximum inflation pressure.” That number is listed on each sidewall, and is much higher than your “recommended tire pressure” of 33 psi, Gary. So, in your case, I’d recommend that you put 35 or 36 psi in the tires and just leave it there.
Is 45 psi too much for tires?
45 psi is simply too high 99% of the time. What is stamped on the tire has to do with maximum load not normal driving. You car comes with a recommendation, usually shown inside the door frame, that is what you want to use. Using too high or too low a pressure will compromise handling, tire wear, and comfort.
How do I know the psi of my tires?
- Purchase a trusted tire pressure gauge.
- Check your tires “cold” – before you’ve driven or at least three hours after you’ve driven.
- Insert tire pressure gauge into the valve stem on your tire.
- Compare the measured psi to the psi found on the sticker inside the driver’s door of your vehicle or in owner’s manual.
Photo in the article by “JPL – NASA”