Tire Tread Depth: Knowing When to Change Your Tires

If you are serious about keeping safe on the road, making sure your tires are safe and roadworthy should be right at the top of your list. You can drive as carefully as you like, but if you set off on a journey with worn tires, you are putting yourself, your passengers, and other road users at risk.

If you don’t know how to tell when your tires need to be changed, it’s important that you learn—measuring the tire tread depth is easy, and it’s not hyperbole to say it could save your life.

If you want to learn how to measure tire tread depth and when you should change your tires, keep reading.

What Is Tire Tread?

It’s a common misconception that the tread of a tire is the pattern of the ‘groove’ in the rubber. In fact, the rubber itself is the tread—the portion of the tire that makes contact with the road. The grooves are in the tread.

Tire tread has a few purposes – it aids traction, and the grooves help displace water and prevent hydroplaning. When tires become worn, the effect the tread has is decreased, therefore making them dangerous.

How to Measure Tire Tread Depth

For standard road tires in the USA, tread depth is measured in 32nds of an inch. New tires are between 10/32″ or 11/32″. The recommended time to have your tires replaced is when the tread is 2/32″, and in many US states, there are legal tread limits.

It should be noted that just if your tread does measure above 2/32″, it doesn’t mean it is safe.

The easiest way to measure tire tread depth is using a penny. At several different points on the tire, place the penny headfirst into one of the tire grooves. If you can see the top of Lincoln’s head, your tire is above 2/32″.

If your tires are over a year old or have high mileage, you should check your tires every two weeks. This may seem excessive, but tread can wear quickly. If you think one or more of your tires may be illegal, we can help.

Do I Replace All My Tires at Once?

If your tires are correctly aligned, it’s unlikely that only one of your tires will be below the legal limit. In FWD cars, the front tires tend to wear more due to them doing more work—picture it like the front tires are pushing the car forward and the rear tires are pulled along.

Rather than replacing all the tires at once, most garages will replace the front tires with the rear ones and fit new tires to the rear. For 4WD cars, you’d expect the wear to be even across all four tires.

Don’t Get Tired of Checking Your Tires

Your tires are important—you could even say they are the most important part of your car in terms of your safety, and the great thing is, they are one of the easiest things to check.

By making regular checks using the penny test, you can be sure you are driving safely and legally. If you discover that your tire tread depth is low, don’t hesitate to make an appointment.