Yesterday I had an oil change at a Mobil 1 lube place. The "service guy", I won't call him a mechanic, started putting air in the tires. I said hold on as I have 30lbs of air in them which is what's on the door label. 2003 DTS. He says "oh don't go by that as the tires need 45lbs of air!" I said no just leave it alone. 45 will go to 50 here in Florida in no time. I have Michelin's on the car. So I come here for opinions. What pressure do you guys keep your tires at?