I've got the stock 20's with Pirellis and run 44psi. Go by the rating on the TIRE not the door sticker.

 

That statement is completely wrong. The pressure rating on the tire is the max safe pressure the tire can handle, NOT what the tire should be run at.

 

Thanks for posting this 05RedFX4,........you saved me a bit of typing.

 

If your running the stock size tire, then the sticker on the door jamb is a good starting point for your tire pressure. The Manufacturer measured the weight of each end of the vehicle and based on their previous knowledge, knows exactly what tire pressure to run to get optimum tire wear for the given vehicle with that size tire.

The above statement does not take into account different brands or load range tires, just size. Now I still have the stock pirelli tires on my truck and I have adjusted the pressure in the front up to 40 psi. The stock 20" pirellis flex to much on the sidewall for my liking and there for bulge too much in the front, so I jacked up the pressure a bit. Anyone remember the Explorer rollovers with firestone tires, well that situation is basically what I'm trying to avoid with my pirellis. The whole debacle between ford/firestone was from ford running too low a reccommended pressure for the given tire and they flexed too much and overheated in hotter conditions and blew out. All anyone needed to do was jack up the pressure in the rear to avoid the problem entirely.