The Penny Tire Test: Measuring Tire Tread Depth

To determine when to change car tires, tread depth is a crucial factor in the life of the tire that you need to check. Several methods can help you know if it's time to change your car's tires. Checking a tire with a penny is one of the simplest ways to check tread depth.

This method requires just a penny and a little time. In this article, we will learn about this method to check when to replace car tires. Also, we will explain tread depth and how to check with a penny.

Penny Tire Test

Penny Tire Test

How to Tell if You Need New Tires?

With just a small penny placed on a tire, an experienced driver can tell if the car is safe to operate or not. Regular tire inspection is an important thing that car drivers should do to save fuel. It ensures their safety before each long trip, as well as minimizing repair costs.

According to experienced drivers, besides tire pressure, drivers should also pay attention to checking tire wear, especially measuring the depth of tire grooves. The spikes on the tires help create friction. It increases the ability to grip the road when the car is moving. But tires can gradually reduce this feature as they are worn.

You can test the tire tread depth at home by conducting a test with a penny. You only need to put a penny in the tread's groove to help quickly determine the depth of this part.

Use a penny and move in the grooves of the remaining tires and if their depth is the same. Then, there is nothing to worry about the condition of your car tires. Although each type of tire has unique characteristics and life expectancy, manufacturers have recommendations about when to replace tires based on the tread depth.

Specifically, if you see the depth less than 2/32 inch, you need to change the car tire because tires are worn. If you don't change your tires soon, it can cause danger when traveling on the road. In addition, pay attention to strange sounds, bulging cracks on the tires, indicators given by the manufacturer, and unusual changes that occur during the vehicle running for maintenance. Replace tires in time to ensure your safety.

Measuring Tire Tread Depth

1. What is tread depth? When should car tires be changed?

The tread depth is the vertical distance between the top of the tread rubber to the bottom of the deepest tread of the tire. We can measure tire tread depth in units of 1/32 of an inch. With new tires, tread depth is usually 10/32 inches or 11/32 inches. For some trucks, SUVs and winter tires may have a deeper tread depth than other models.

  • Tire tread depth over 6/32 inches: ensure good functionality.
  • If a tread depth of 5/32 inches will interfere with wet driving, consider changing your tires.
  • If the tread depth is 4/32 inches, change the tire as soon as possible.
  • If the tread depth is 2/32 inches, you need to change the tire immediately.

We always recommend that customers need to change their tires when their tread depth is 4/32 inches. Because the tire's performance will decrease before the tread reaches 2/32 inches, your tires will be a hazard if the tread depth is at 2/32 inches.

2. Why is treadwear important?

As life gets busier and busier, you can forget about tread depth as you focus more on where you are going. For tire maintenance, tread depth is one of the most important things to ensure vehicle safety and performance.

With worn tires, it becomes progressively less drainable. So, the risk of hydroplaning increases, especially at high speeds. Loss of traction is also a concern because worn tread makes the vehicle slow to react to adverse weather. In addition, tires with low tread are more prone to punctures and can also lose pressure leading to sudden tire bursts. Punctures can damage the tire, causing you to lose control of the vehicle.

So, you need to make sure your tires have the proper tread depth for safe driving. Worn tires need to be replaced. One of the first tire maintenance tricks many car owners learn is to check the tread with a penny.

Penny Tire Test

How to Check Tire Tread with a Penny?

After understanding tread depth and its importance, you can find out if your tread depth is satisfactory. Find a penny and go to your car. It is time to do a check tire tread depth. This test is not difficult. However, many people do not know how to check their tires properly or do not know what the results mean. First, to measure the tread depth, you need to know how to place the penny. Place a penny (with Lincoln's head upside down and facing you) between the veins on your tire.

On a new tire with the tread depth, the top of Lincoln's head will disappear. But if you can see the top of Lincoln's head, your tread is too shallow and worn. If the entire head is visible, it is a sign that the tire is too worn and the tread depth is only 2/32 inches or fewer. You need to replace the tire immediately.

Note that you should check all four tires. Then, check multiple places around each tire and pay attention to the most worn areas. Maybe some parts of your tire do not meet the requirements, but others do. You should change the tire when any area is unsatisfactory.

Penny Tire Test


Checking the tread depth with a penny is the simplest way you can do it yourself at home. So check your tread depth with a penny regularly so you can plan to buy new tires when you need them. However, for accuracy, you should use a tread depth gauge, check the tire wear indicator bar. Or better yet, take your car to a tire dealer for advice when you think your tires may need to be replaced.

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