When your tire treads wear thin, you could be in for a slippery ride—literally. Luckily, you can spot dangerous tread depth using only a penny, and Honest Abe’s face! The penny test is quick, easy, and can help you know exactly when to replace tires.
The Penny Test
To check your tread depth, you don’t need any fancy tools or expert knowledge. Grab a penny, and you have everything you need!
- Place your penny into a tread groove upside down. In other words, your penny should be going into the tread headfirst!
- Examine the part of the penny that’s showing. If you can see the top of Abe’s head, your tread is shallow.
- Repeat the penny test in several grooves of your tires. If you can always see the top of his head, your tire is worn and it’s time for a replacement!
For reference, the distance between the top of a penny and Abe’s head is about 2/32nd of an inch. If you can see the top of his head, your tread is less than 2/32nd of an inch and your safety may be at risk. Depending on where you live, continuing to drive on such thin tread could actually be against the law.
“Most states require a minimum of 2/32 of an inch (approximately 1.6 mm) of tread, but two require less, some have no requirements, and some defer to the federal criterion for commercial vehicle safety inspections,” reports the National Center for Biotechnology Information.
Why check tire tread depth?
With adequate tire tread depth, your car is able to grip the road. This is especially important when roads are snowy or wet, or when you’re driving on less-than-ideal surfaces. Once tread becomes shallow, your tires are more prone to slipping and sliding, creating a dangerous situation for yourself and other drivers on the road.
When your tires are worn, other components of your vehicle can begin to wear prematurely, too, as your vehicle experiences excess strain. While new tires can be a big investment, they’re an investment worth making.
Check your tire tread depth today!
Reach into your pocket and pull out your spare change. Give the penny test a try—it only takes a few minutes—and find out if it’s the right time to replace your tires. If you’re short on change, just find your nearest Firestone Complete Auto Care. Our stores offer free tire inspections that include tire tread depth measurement!