Factory Specs on Tire Pressure?

I have been doing wheel alignments for over 25 years and the best air pressure i have found for passenger tires is 32 - 35 PSI all the way around
At 32 PSI you get a softer ride and do not loose a lot of wear. The best wear is at 35 PSI but some cars are rough around town & city streets. The other thing to remember is to keep your tires rotated if possible. When you get into 60 and 50 series tires you will have to play with the pressures as high pressures will wear the centre of the tires and too low will wear the shoulders.