text.skipToContent text.skipToNavigation


Tread is a series of grooves which provide your car’s tires with traction. These grooves between tread blocks act as channels that divert water, snow, and other slick elements away from the tire to help you maintain traction on slippery surfaces. Without tread, those elements can lift your tires off the road.

When is it Time to Replace Your Tires?

Tire tread depth in the U.S. is measured in 32nds of an inch, and several states require you to replace them when depth falls to 2/32". The U.S. Department of Transportation also recommends replacing your tires when they diminish to that depth. New tires, on average, start with 10/32” to 11/32” of original tread depth. That tread wears over time due to normal driving, but wear can become uneven due to driving habits and neglecting tire rotation among other things.

How Can You Check the Tread Depth of Your Tires?

Paying attention to a tire’s tread is one of the easiest ways to monitor its lifespan. But how do you check your tire’s depth? Some tires have tread wear bars that will indicate when tire tread reaches 2/32". Tread depth gauges are also available at Pep Boys. But the easiest way to determine the depth of your tire's tread is by giving them the "penny test."

What is the Penny Test?

The penny test is an easy and accurate way to measure tire tread depth.

Take a penny and place it between the tire tread blocks with Lincoln’s head upside down and facing you. If Lincoln's head is buried, your tires still have more than 2/32" of tread. Your tires need to be replaced if the head is visible.

After taking the penny test, a tire’s tread can be visually inspected to spot other issues. There are six common types of irregular wear to look for, but two are most common. Center wear is when your tire is worn down the middle and caused by over-inflation. Shoulder wear happens when the sides of the tire wear quicker than the middle of the tire and tends to be caused by under-inflation. A misalignment could also cause wear issues, especially when there’s excessive wear on the camber or toe.

Regardless of whether you use the penny test or a depth gauge to determine your tread depth, it is important to test your tires in multiple areas. Misalignment, not rotating your tires, and other issues can cause uneven wear. Schedule an appointment at your local Pep Boys if it's time to replace your tires or you're in need of a wheel alignment or tire rotation.