Watch and learn how to measure tire tread
How to Check Tire Tread
Updated on Oct. 31, 2024
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What Is the Optimal Tread for a Tire?
When your tires are worn, you risk a blowout, but that’s just one reason to replace them. Another reason is that worn tires don’t grip the road securely, and in rainy or snowy conditions, you could find yourself hydroplaning into a tree. A third reason is that your car’s engine has to work harder and consumes more gas when the tires are worn. My own Subaru gets about 33 mpg on new tires and less than 30 mpg when the tires need to be replaced.
The minimum legal limit for tire tread depth is 2/32 of an inch, but for good tire maintenance, Goodyear recommends keeping a close eye on your tire tread once the depth reaches 4/32 of an inch, according to assistant district manage Jason Banys. So how do you measure tire depth? Goodyear recommends four methods.
What Ways Are There to Measure the Tire’s Tread
You can use more than one method to tell if your tire tread isn’t up to par, from simple visuals using a coin to handy tools that will tell you the tread depth.
The Penny Test
The penny test (shown below) is the easy way to check a tire tread’s depth when you don’t have a depth gauge. Banys instructs: “Insert a penny into your tire’s tread groove with Lincoln’s head upside down and facing you. If you can see all of the head, your tire tread depth is less than 2/32 inch and it’s time to replace your tires.”
The Quarter Test
Insert a quarter into your tread groove. If the tread touches Washington’s head, you have at least 4/32 inch of tread remaining. and Banys says you should consider buying new tires soon.
Tire Tread Depth Gauge
You can pick up a tire tread depth gauge at any auto parts store for about $5. Typical tread depth gauges measure in 32nds of an inch (25 millimeters). Some gauges have a needle-like design with a portion that expands to measure tread depth. Because tires wear unevenly, Paige recommends taking measurements in different locations around the tire.
Tread Wear Indicator
Tire wear indicators are located less than an inch (2/32 of an inch) from the bottom of the tread groove. When the tread wears down to become even with this level, the tire should be replaced.
When to Replace Tires
It’s common for drivers to ignore their tires until driving on them actually becomes dangerous. Tire maintenance should be a part of your routine car maintenance, and these are signs your tires need to be replaced:
- Tread depth: Replace your tires when you determine the tread depth is 2/32 of an inch or less, using one of the methods above.
- Bulges: If you see bulges in the sidewall, the tire needs to be replaced immediately, or you could have a blowout.
- Cracks: Cracks in the sidewall, like bulges, are another sign that a tire needs to be replaced.
FAQ
How often should I check my tire tread?
According to Banys, Goodyear recommends checking the tire tread depth every 3,000 miles (5,000 km.) Check more frequently when the depth reaches 4/32 of an inch.
What are other signs your tires may need repair or replacement?
Cracks and bulges in the sidewalls are obvious signs. You should also consider replacing your tires when you’re experiencing a shaky ride and can feel every bump in the road or when your gas mileage decreases significantly.
About the Expert
- Jason Banys is the assistant district manager for Goodyear Tires.
