can someone tell me what the correct tire pressure for 235/60/16 would be for the sts the door label says 32psi but i feel its better at 40psi and how much air can i put in that wont be to much.

i have 225/60/16 and i run 38 in the front and 36 in the back, cold tires.

32 psi is what Cadillac recommends. Lower will give you a better ride. Higher will give you better milage. Max is listed on the sidewall. I would suspect at 40, you'll see wear in the center of the tread and a shorter tire life.