I sheepishly have to admit that I haven't even checked the pressure since buying the car in October. I have a little DC powered compressor that I can use in the garage but the tires are cold and I know they expand when heated so I'm cautious about filling them up to 44psi, only to find out that they are really 50+ when they come up to temperature. Any suggestions? (and suggesting that I fill them up when I get home from a drive somewhere hasn't worked for me so far because I always forget upon pulling into the garage).

Thanks!

 

If you set the tire pressure within the range listed on the sidewall when the tire is "cold", then you will be within the safety margin for tire pressure when the tire is hot. The pressure indeed will be higher when its hot, but it's not relative since no manufacturer talks about anything but cold pressure. Also, outside air temperature isn't a significant factor. As you pointed out, its the tire that gets hot from friction. Measuring the tire pressure after the tires have been not moving for three hours should give you the correct pressure reading.

The NHSTA has a good reference about tires and the federal standards that regulate them. Look at: http://www.nhtsa.dot.gov/cars/rules/.../brochure.html

If you're still worried, then just set them cold at 42 or even 40 PSI.

Good Luck.

 

Cool, then I guess I was asking a stupid question . I've raised them all from the 35 they were at to 40psi for some initial testing and I may add more later. It's kinda odd that one one spot, the tire says max inflation 40psi and then on another, it says 44psi...