Even just a pound or two of underinflation in your tires can be a problem. Why, though? There are several reasons.
Fuel economy: If you ever rode a bicycle with a low tire, you know that it feels like you’re riding through wet cement due to the added rolling resistance. The same thing is happening with your car, and compromising your fuel economy. Over the course of 10,000 miles per year, that can add up to 150 gallons of gas or $500 out of your pocket!
Handling: Low tire pressure means poorer control and longer stopping distances. At high speeds, in particular, this can be downright hazardous.
Premature tire wear: Underinflated tires are under a lot of stress, especially their steel ...[more]