[bobcowan]

That will vary a little bit from tire to tire. Don't go by the number stamped on the sidewall. That's the max inflation pressure.

Generally speaking you want about 1psi per 100#. If your car weighs 2600# wet and loade, you should start with about 26psi. But, that's just the starting point. There's two ways to determine the correct weight. Both of these work for any tire on any 4 wheeled vehicle.

1. Use a tire pyrometer. After driving down the highway, pull over and check temps on each edge and in the middle. If temp is highest in the middle it'sover inflated. If it's lowest in the middle, it's under inflated. If it's highest on one of the edges, the alignment is off. This will give you the most accurate results.

2. Use blackboard chalk. Drive down the highway and get the tires nice and warm. Pull over, and place a heavy chalk line across the tread. Drive foreward about 20'. Check the chalk line to see where it's been rubbed off the most. Thin in the middle means it's over inflated.

Be sure to check both front and rear. My car is almost perfectly balanced, so I use 26psi front and rear. I determined the pressure with a tire pyrometer that I bought off e-bay for $50