Door sticker calls for 30 psi cold on stock 225/75R15. With 30-33 in tires, run 26-30 psi street, 12-18 psi airdown for trails.
Factory tire pressure on stock 225/75R15 or 215/75R15 tires is 30 psi front and rear cold per the door jamb sticker. Pressure should rise about 4-6 psi after a long highway drive - if it rises more, you started too low. For oversized tires (31x10.5R15, 32x11.5R15, 33x12.5R15) the door spec is wrong - those are E-rated or D-rated 8-10 ply tires designed for higher load and stiffer sidewall. General consensus: 32-inch BFG KO2 or similar, run 26-28 psi cold for best ride and tire life; 33-inch run 24-28 psi cold. Use the chalk test (chalk the tread, drive on flat ground, look at chalk wear - even wear means correct pressure) to fine-tune. Off-road airing down: 15-20 psi for sand and snow, 10-15 psi for rocks, never below 8 psi on a non-beadlock wheel. ARB E-Z Deflator or Staun deflators speed up airing down on the trail; a quality 12V compressor (ARB CKMTA12 or Viair 400P) is mandatory if you air down.
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.