The temp was in the upper 60's and I had driven over 40 miles when my light came on but my tire's are inflated to 32 PSI. This is the PSI. as delivered. My car has 1200 miles on it. The sticker in the door say's 32 pounds for the R/T 18 inch 55's. I agree that a couple extra pounds will not hurt. So I will raise the pressure to 35 PSI.