I inflated my tires to 38/36 over the winter. In fact, it was a very cold day when I inflated my tires; definitely below freezing. So when I got my first oil change and tire rotation in June, the tires had of course gained some pressure. I've read a rule of thumb that for every 10 degrees Fahrenheit, tire pressure goes up one psi. Seems about right, as the tech reprimanded me for having the tires up near 50psi. I realize it's unsafe to have the tires that inflated that high. I hadn't really thought about the tire pressure as summer arrived, because my mileage was just so great. I was averaging 53mpg, with country road mileage of 60! Now that my pressures are back to more reasonable levels (44/42), my mileage is languishing in the high 40s. I only have 6,000 miles on the car, so I guess I thought I was hitting a break-in point, combined with summer. Anyone else had over-inflation experience?
buy your self a good tire pressure gauge, don't rely on the ones at the gas station. I use a digital and have one for the wifes car as well and had both checked by a pneumatics specialist and they are both 1/2 PSI low at 50 PSI. and right on at 25 PSI. both different manufactures as well. There is no proof that the one the tech used was accurate.
