I believe that the factory recommended tire pressures for these trucks are WAY underrated, hense the problem the the Explorer/Firstone war. Part of that problem, in my opinion, was the the factory recommended tire pressure for the Explorer was less than 30 psi. I believe that Ford underrates pressures to improve ride quality, but you lose handling quality with underinflated tires, that is on the road anyway, offroad is a whole other story. I believe that the tires were getting too hot and had tread separation. I will admit that if the tires were made better they would not have come apart under low pressures, but I also believe that Ford should have recommended higher tire pressures, but to get back to the point - cuz i know i dont want to get in the Ford/firestone war. I have the 17" wheels on my X and they say on the tire that the max pressure is 44 psi when cold. I keep 40 psi in all four corners. I have watched tread wear closely and have not noticed any uneven wear especially in the middle, where you would expect it from overinflation. The ride of the truck is not that much noticeable with the higher pressure. Well, hope i answered you question.