Quick Navigation
A tire’s tread can be thought of as a series of ribs or grooves that run the whole circle of the tire.
This raised section of the tread pushes water away, making it possible for the vehicle to be driven safely in adverse weather situations such as rain and snow.
However, when the tire tread wears out, the tire loses traction on the road, which makes it more difficult for the braking and steering systems to accomplish their jobs, particularly when the road is wet.
When the tire tread depth reaches 2/32 inches, it is no longer safe to operate a motor vehicle.
But how exactly does one measure the tread depth of a tire?
A tire tread depth gauge, a penny, a quarter, an indicator that measures tread wear, or a tire tread wear gauge can all be used to measure the depth of a tire’s tread.
Checking The Tire Wear
The Penny Test
A penny is the standard tool for determining the amount of tread depth on a tire in the United States.
Place the penny into the tire groove so that the image of Abraham Lincoln’s head goes in first.
- If you can see the entire head of Abraham Lincoln, this indicates that the tread depth of the tire is less than 2/32 inches.
- If you check multiple grooves on the tire and get the same result each time, you will need to replace the tire.
- It is reasonable to presume that the remaining tread on your tire is 4/32 inches if even a small portion of Abraham Lincoln’s skull can be seen hiding in the groove.
Because of the decreased vehicle performance, some people recommend replacing tires as early as this measurement, which is the tread depth of the tire.
It’s possible that the tires won’t hold up under severe driving conditions.
Procedure For This Method
- Pick up a penny. Use the side of Abraham Lincoln.
- Lincoln’s head should be facing the tread groove when the coin is turned upside down.
- In between the tire tread, bury the penny.
- Verify if you can see Lincoln’s head. If it is, the tread on the tires is shallower than the required minimum tread depth, making them unsafe to use.
Lincoln’s head would only partially fit in the groove, meaning that the tread would still be larger than 2/32 inches.
- Make sure to test the tire all around. Examine numerous locations, paying particular attention to worn-out-looking regions.
The Quarter Test
The quarter test is yet another method for determining the level of tread on your tires.
When conducting this test tread on tires, the depth of the tire’s tread is tested by utilizing a head of George Washington.
- If George Washington’s head was completely hidden or not visible at all when placed in between the tread grooves, then the tires would be safer to drive on. New tires basically have a tread depth of 10/32 to 11/32 inches, which translates to 8 to 9 millimeters.
- The tires are still safe to drive on with 4/32 inches of tread remaining, even if George Washington’s head contacts the rib of the tire when you install it face down (so that it is visible to you).
- If you can make out George Washington’s head on the quarter, the tread depth of the tire is less than 2/32 of an inch. This demands the replacement of the tire right now.
You can gain confidence in the accuracy of your tire tread measurement by doing the penny test or testing the tread depth of your tires with a gauge.
Procedure For This Method
- Pick up a quarter. Take the George Washington side.
- Place the quarter into the tire with George Washington’s head pointing in the direction of the tire ribs.
- The tires should be changed if you can see Washington’s head.
At 4/32 inches deep, the tread should be deep enough to reach Washington’s head.
- The tire should be tested in various locations. Focus on places that are clearly worn out.
Check the Tread Wear Indicator on the Tires
Because each tire has its own built-in tire tread indicator or wears gauge, checking the tread wear on a tire does not require any additional instruments.
They take the form of six bars that are spread out over the tread ribs.
When the tread depth exceeds the minimum legal requirement of 2/32 inches (or 1.6 millimeters), the bar is allowed to become visible.
Different grades of the bar were used in the construction of some tires, including 8/32, 6/32, 4/32, and 2/32, respectively.
Therefore, check the tread grooves of the entire tire to ensure that they adhere to the tire wear indicator chart.
Pickup trucks and other large vehicles often have tires with a tread depth of between 15/32 and 20/32 inches when they are brand new.
Procedure For This Method
- On the tread shoulder, search for the letters TWI (Tread Wear Indicator).
- The tread wear indicators, or bars, are located at the base of the tread directly across from that location.
- It is deemed dangerous or worn out if the tread is flooded with or exposed to the same degree as the wear bars.
- Some tires include numbers in the center of the tread rib that represent the millimeters of tread depth. These numbers decrease with tire aging. The amount of tread still on the tire is indicated by the visible number.
Using a Tread Depth Gauge to Take Measurements
Utilize a tire tread depth gauge in order to obtain an accurate measurement of the depth of the tread on your tires.
This instrument cannot, of course, measure a tread that is completely worn out or bald.
Look for a tread with the shallowest depth.
First, the gauge pin must be inserted into the groove, and then it must be pressed toward the tread. This instrument offers precise readings in both inches and millimeters.
Note: They can be acquired for close to $4 in automobile shops where such items are sold.
What you need to have ready: a penny, a quarter, a tread depth gauge, or a tire tread indicator.
- The penny test is a simple method for determining whether or not the tread depth of a tire meets the minimum requirement of 2/32 inches.
- The quarter is another coin that can be used to determine whether or not the tires are in good condition at 4/32 inches.
- Tire Tread Indicators are rubber notches that have been elevated to 2/32 inches from their original position. When the indications flush, it implies the tires have been worn down to a level where they are no longer safe to drive on.
- The most precise measurement of tire tread depth can be obtained with a tread depth gauge.
Procedure For This Method
- Verify the scale you intend to use for measurement (inches or millimeters).
- On top of a tire groove, position the tread depth gauge.
- Activate the gauge.
- When you locate a number with a line beneath it, rotate the scale.
- The measurement of tire tread depth is shown as the first number.
When is the Most Appropriate Time to Check the Depth of the Tire Tread?
In general, the tread depth of your tires ought to be examined every 5,000 kilometers (or 3,000 miles).
It is also a good idea to check the tread on your tires on a seasonal basis or whenever you change your tires for the winter or summer.
Conclusion
Knowing how to measure tire tread depth will allow you to keep a careful eye on the condition of your tires.
With or without a gauge, you can determine the tread depth of your tires. The coin tests are useful for estimating tire tread depth.
The ideal approach to check tire tread, however, is with a tire tread depth tester if you want to avoid car accidents.
The minimum tire tread depth required by law is 2/32 inches, although it is safer to schedule tire replacement as soon as the tread depth reaches 4/32 inches.
Kevin has been hanging around cars and automobile magazines since he knew what a car is. He grew up in his father’s 1995 Mercedes E320 Wagon and Volkwagon Phaeton W12 2004. He rides his first car, a manual 1979 Porche 911SC.
Currently, he owns an Acura Integra GS-R. During his childhood, he showed a keen interest in how things actually work and fix them. This passion transforms into his eternal love for cars and bestows him an ideal position in one of the leading automobile companies; whenever he finds time, he takes out his Acura and opts for the longest possible route to find hidden wholesome pleasure in a road trip.
Want to read some of the articles written by Kevin? Head to our blog section to find out all the articles written by Kevin.