Diagnosing Tire Wear: Tire Pressure and Alignment

Posted Monday, Aug 05, 2019

Hopefully, you’re periodically checking the wear on your tires; it can help you extend the life of your tires and get your money’s worth out of them. Obviously, tires can wear in myriad ways, and each way tells you something about that specific tire/wheel. Following is the procedure for diagnosing tire wear appropriately.

The ways in which tires typically wear are: center, inside shoulder, outside shoulder, or both shoulders. If you note that a tire is wearing in the center, you can bet that the tire is over-inflated. Because of the excess pressure, the center of the tire is pushed outward and stands taller than both shoulders; hence, the center is carrying the weight of the vehicle and will thus wear more quickly than the shoulders (which are barely contacting the road). Not only does this cause the tire to wear prematurely, it reduces the contact patch of that tire and gives you less traction; this can quickly become a safety issue.

If you notice that both shoulders are wearing more quickly than the center, it’s a safe bet that the tire is under-inflated. Because of the lack of air pressure, the sidewalls are having to carry the weight of the car thus placing all the force on the shoulders and leaving the center with little work to do. Once again, this causes premature wearing, but also creates a safety issue in that the tire is less effective in evacuating rainwater from under the tire.

If you see that the tire is wearing predominantly on the inside shoulder or outside shoulder, you have an alignment problem. If tires from opposite sides, like both front tires, show inside/outside shoulder wear, then you probably have an issue with toe-in. If only one tire has inside/outside shoulder wear, you may have camber issues. However, the only thing you can be sure of is that you need an alignment; hence, a trip to the alignment shop is inevitable.

What you want to see is that all four tires are wearing uniformly across the tread. If so, it means they are properly inflated and aligned. By diagnosing tire wear periodically, you can ensure your tires’ longevity, and possibly even your own.