2008 Hyundai Elantra Tire gauge

ROCKETMAN007

MEMBER
2008 HYUNDAI ELANTRA
74,150 MILES

I purchased a new tire gauge and would like to determine the true pressure based on the reading, the outdoor temperature, and the number of miles traveled immediately before testing. Assuming I can't test or add air first thing in the day I assume a minimal number of miles traveled will produce the most maximum amount of heat from that factor? Maybe after say 20 miles it is at the hottest as it can be when it is 70F outdoors or something? Any formula that combines all these things together?

1 Reply

CARADIODOC

MECHANIC
33,908 POSTS

It sounds like you're seriously over-thinking the issue. I've been a suspension and alignment specialist for over 25 years and have never been asked these questions or given it much thought. All tire pressures are listed somewhere on the car and are for cold tires. The pressures are expected to go up when the tires heat up so if you want to know what normal is, set the pressures when they're cold, drive your normal distance, then measure the pressures when they're hot.

The only conversion factor I've ever heard of is that, as I recall, the pressure will drop a pound for every ten degrees F, but that's for a tire that's standing still. Every tire is going to heat up differently based on numerous characteristics such as thickness of the rubber, how much the sidewalls flex, (which builds heat quickly), how much the tire sticks to the road, (friction also creates heat). No two brands of tire will be the same. Your type of driving will also affect how much heat builds up. Stop and go city driving generates a lot of heat. Straight highway driving, ... Not so much. If you've ever watched an interview of a NASCAR race driver, they know all about how to cool off their tires while going 190 mph, and how to get them warmed up when they want to.