CHOOSING YOUR TIRES
The Penny Test
Insert a penny into your tire's tread groove with Lincoln's head upside down and facing you. If you can see all of Lincoln's head, your tire tread depth is less than 2/32 inch and it's time to replace your tires.
The Quarter Test
Another easy coin test to measure tread depth is the quarter test. Insert a quarter into your tread groove. If the tread touches Washington's head, you have at least 4/32 inch of tread remaining.
Tire Tread Wear Indicator
You can also check the tread wear indicator. You can find the tread wear indicator less than an inch (2/32 of an inch) from the bottom of the tread groove. When the tread wears down to become even with this level, the tire should be replaced.
Tire Manufacturing Date
Check the manufacturing date of your tires by examining the sidewalls. The manufacturing date is shown through the last four digits of the number that starts with DOT. The first two digits represent the week made and the second two represent the year made.