I'm a new 05 Roadster owner and have never had a TPMS before. Had the car for two days when the system went off, added a couple of pounds of air (35 PSI ) and the system corrected itself. My problem is now I monitor the pressure all the time! (I know I don't have to). Have read all the articles about tire problems with the Z and have become paranoid.

I have OEM Bridgestone Potenza REO040 245/45R18s.
My question is what is the acceptable PSI variance? This AM The range was from 32-37....37 was reached after 25 minutes of driving, of which approx 10 minutes was at 70 MPH. I have read strings in this forum where the pressure reaches 40+ psi.

Is it better to error on the high or low side?

Appreciate any advice.

 

I wouldn't worry so much about the warm tire pressure. As long as you have a consistent cold tire pressure, you should be fine. It is completely normal for your tires to increase in pressure by a few psi when warm. (after driving) If your TPS goes off while driving, and you fill the tire at that time, you need to fill it with a few extra psi and/or recheck the tire after it cools.