[Jethrow]

On most of the yankee sites the old 1 psi per 100 lb rule is quoted. So if our cars weigh say 2400 lbs (1100 kg approx) then 24 psi is a good starting point.

Seems about right too for my HSV Clubsport which weighs around 3700 lbs and I like to run that about 38 psi.