I thought that I remembered reading about a trick to determine the correct tire pressure on here years ago? The trick involved using chalk on the tires. I've searched the forum but can't seem to find it. Does anyone remember this trick? Thanks in advance.
Grab some sidewalk chalk, and mark about 6-8 inches of the tire.
Drive the Jeep backwards about 50 feet, then go forward again to the starting point. Get out and take a look.
The pattern above is nearly perfect.The chalk is worn evenly. This is a 35" tire with about 31 psi. On a mud tire, the very edges of the outer lugs will still show some untouched chalk and nothing can be done about it. They'll eventually wear with the center over time. All terrains and finer treads should wear all the way across evenly.
If the center shows fresh chalk, then the tire is underinflated. If the center shows worn chalk but the rest of the tread doesn't, then the tire is overinflated. If just one edge is worn, there is an alignment problem.