Actually that depends on the tire. Somewhere on the tire should be reccommended tire pressure and that is what I would use on the road. We dont want to have a problem with temp build up with to little pressure as was the problem with Ford Explorers and Firestone. Ford suggested under inflation to get a better ride and that did not work to well did it!!!! Now on the track you can drop pressure some to get better launched!!!
So you're saying I should go with the recommendation on the tire and not the one in the globebox? I thought the weight of the car still determined what PSI you should run at and that's why they posted it in the car? Either way... I don't think my car has 275x40x17 in the glovebox, just the 205 and 255 maybe.
Those PSI numbers are based on weight of the car. I suggest following the tire manufactures numbers before Car manufacture numbers. I say go with tire numbers and monitor your tires wear and if the outside is wearing to fast make sure you are in alignment and increase pressure by a slight amount if the center of the tire is wearing and the outside threads are not wearing back down the pressure slightly. But in all actuallity the fluctuation of a couple of PSI is nothing to worry about.