Tires speak, and they are undernourished

For those of us who live in a world of tires on a day-to-day basis, talking tires isn't necessarily considered out of the ordinary. But for even someone who isn't surrounded by tires as much as we are, tires are actually fairly good at telling what ails them and when its time to do something to keep them "healthy."

Undernourished: Much like when people lose weight if they don't eat, tires actually dissipate air out through their rubber skin if not topped off. Tire rubber is permeable to air molecules and CR studies have shown even sitting still a tire can lose as much as 40 percent of its inflation pressure in a year's time. The problem is that they may not show it visually.

No worse and no more time consuming than taking your temperature when you're ill, a check with a tire-pressure gauge once a month is the best way preventative medicine. A quick check can make sure that your tires have the proper inflation to handle and wear as they were intended, as well as delivery the proper fuel economy.

Under-inflated tires have higher rolling resistance, which can lower fuel economy. Under-inflated tires also flex more and can't carry as much load as when they're correctly inflated. Hence, such tires generate more heat than normal, which can potentially lead to a tire failure or blowout. Tire-pressure monitoring systems, required on new cars starting this coming model year (2007) will help tires get their message across with a signal in the dash letting you know when inflation pressures are low. But on older models, and even as good policy with new ones, it is best to use a tire gauge as part of your monthly car care routine.

--Gene Petersen