So I took my STS on its first >50 mile roadtrip last weekend. I figured it would be good to check the tire pressure (I know: I should do it every week :thepan. I checked the driver's door sticker and it says for 235-ZR-16 tires they should be at 30 PSI. Well, the Zs are long gone and she's wearing a nearly new set of BFG 235-R-16s. Is there a different pressure recommendation for non-Z rated tires? Also just curious as to people's results with tread life and gas mileage on these cars as related to tires - 30 PSI seems kinda low, I couldn't convince myself to go below 32. And one last thing - does the Z sticker on the door mean my car doesn't have a speed limiter?