My wife's new car ($$$$$$) checks itself out every time you start it. I live at 4,000 elevation and the closest town is at 500 ft. and we sometimes go up as high as 7,000 ft. If the car is accurate when it checks itself out, tire pressures of 36 psi seldom change at all. And no, it doesn't adjust its own tire pressure. Maybe our next car will do that. LOL