Checking your tires is like going to the dentist, says Johnny Unser, former race-car driver and five-time veteran of the Indy 500. “It’s something we don’t do often enough, that we put off until we absolutely have to.”
According to the National Highway Traffic Safety Administration (NHTSA), tire failure causes around 11,000 car crashes each year. Both Unser and the NHTSA recommend doing a quick tire inspection once a month. Here’s what to look for:
- Bulges, gouges or cracks
When a tire deflates, it bulges at the sides. Unser says this is a sign of low tire pressure or a slow air leak. “If you see cracks in the sidewall, gouges or anything that looks odd, take it in to your dealer and have them look at it.”
- Tread wear
The old-school penny test is one way to check your treads: Place a penny into the tread, with Lincoln’s head pointing down. If you can still see the top of his noggin, the tread is dangerously low. Most modern tires, however, have wear bars: bits of rubber woven into the pattern at a specific depth. “You can find the wear bars that go across the groove, and if the tread pattern is worn down to that wear bar, you need to replace your tire,” says Unser.
- Tire pressure
Tires deflate at a rate of about one pound per square inch (PSI) per month. “You’re not going to wear your tires down in a month,” Unser says, “but you should check that you have the right inflation pressure.”
Tire pressure drops in extreme cold. The challenge in summer, says Unser, is “excessive heat buildup in the tire.” If you’re heading out on a road trip with an underinflated tire, it will generate more heat and wear out faster.
Watch out for vibration or thumping when you’re driving. If it feels like it’s coming from under the seats, the rear tires may be out of balance. Vibration from the steering wheel could indicate suspension issues. Unser says anything less than a smooth ride means you should take your car in to the dealer.
When it’s time to replace your tires, Unser recommends doing so in pairs or all four at a time for better performance and traction and, ultimately, a safer ride.