Tires say the maximum psi, not what they SHOULD be at. The PSI you should use for any car is printed on the inside of your driver side door. But thats just the suggested psi which depending on the car is recommended for an even of handling, comfort, and gas mileage.
Tune the tires to a certain psi, the car can perform better at a different psi then whats recommended so play around with it. higher psi in the front then the rear is a start with our cars.