
According to the National Highway Traffic Safety Administration, tire failure causes 11,000 car crashes each year. They recommend doing a quick tire inspection once a month.
Here's what to look for:
- Bulges, Gouges or CracksÂ
When a tire deflates, it bulges at the sides. 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 wearÂ
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
 - Tire pressureÂ
Tires deflate at a rate of about one pound per square inch (PSI) per month. Check that you have the right inflation pressure.
 - TemperatureÂ
Tire pressure drops in extreme cold, in summer an under-inflated tire will generate more heat and wear out faster.
 - VibrationÂ
Watch out for vibration 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. Anything less than a smooth ride means you should take your car in to the dealer.
When it's time to replace your tires  do so in pairs or all four at a time for better performance and traction and, ultimately, a safer ride.