The legal minimum tire tread depth in the United States is 2/32” and many tire experts recommend replacing tires at 4/32”-6/32” tread depth or less, especially for tire types that benefit from a deeper tread (snow tires, all-terrain tires, or mud tires). Testing multiple winter tire brands at 5/32”-6/32” tread depth (or 50% of original tread depth), Consumer Reports saw a 14.5% decline in snow traction when accelerating, and a 7% increase in wet stopping distance compared to the tires’ original tread depth 2 .\
How to tell if your tire tread depth is too low, and you need to replace your tires:\
Use a tire tread depth gauge for a precise measurement.\
Take the U.S. Penny Test: Insert a penny (head first) into your tire tread. If you can see the top of Lincoln’s head, it’s time for new tires. If the top of Lincoln’s head is covered, your tread is deeper than 2/32”. On the tail side, if the top of the Lincoln Memorial is covered, your tread is deeper than 6/32”.\
Take the Canadian nickel test: If the top of Queen Elizabeth’s crown is covered, your tread is deeper than 2/32”.\
Take the U.S. Quarter Test: If the top of Washington’s head is covered, your tire tread is deeper than 4/32”.\
Take the Canadian Quarter Test: If the caribou’s nose is covered, your tire tread is deeper than 6/32”,\
Check the wear bars: Tire wear bars are situated at 2/32” of tread depth, so if any wear bar is worn, replace the tire right away. It’s below the legal minimum tread depth.\
Check tread depth on several parts of the tire, especially if you see uneven wear patterns. And talk to a Midas tire expert to help you decide how low your tread depth can go.\