Here’s how to check your tire’s tread level with the penny test and the quarter test. #tires, by Fix it Flip on YouTube. 2 min 14 s.
- Video length
- 2 min 14 s
- Time to do it
- 5 minutes
- Difficulty
- Easy
- Steps
- 7
What you need
Steps
Park on level ground, set the parking brake and switch off the engine. Brush dirt out of the tread grooves so you can see the bottom.
Find the wear bars: small raised bars running across the grooves. If the tread surface is level with a wear bar, the tire is at 2/32 inch and is worn out.
Push a penny into a groove with Lincoln's head pointing down. If you can see the whole top of his head, the tread is below 2/32 inch, so replace the tire.
Now use a quarter with Washington's head down. If the top of his head shows above the tread, you have less than 4/32 inch, which means weak grip in the rain.
Test at three points across the tread, inner, middle and outer edge, and at four spots around the tire. Wear is rarely even, and one bad spot is enough to fail.
Check all four tires plus the spare. Note any tire worn more on one edge, since that usually points to bad alignment or the wrong pressure.
If the tread passes, set the pressures to the door jamb sticker when the tires are cold, then repeat the coin test once a month.
Tips and common mistakes
Measure when the tires are cold and dry, and never do the test with the car on a jack.
The coin test is a rough pass or fail check. A cheap tread depth gauge gives a real number in 32nds of an inch or mm.
Replace at 4/32 inch if you often drive in heavy rain, well before the legal 2/32 inch limit.
While you are down there, look for cracks, bulges or exposed cords. Any of those means a new tire whatever the penny says.
Questions
What does 2/32 inch actually mean?
It is the legal minimum tread depth in most places, about 1.6 mm. Below that the tire cannot clear water from under itself and grip drops sharply.
How accurate is the coin test?
It gives a yes or no answer at two depths, not a precise figure. Use a tread depth gauge if you want to track wear month by month.
Can I use a different coin?
The penny and quarter work because the height of the head matches the 2/32 and 4/32 inch marks. Other coins only work if you measure their height first.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
