The Washington Quarter Test

 

Tread depth is measured in 32nds of an inch. New tires start with 10/32 or 11/32 inch. For safety and road handling confidence, your tires should have a tread depth of at least 4/32 of an inch. That’s just to the top of George Washington’s head on a quarter placed upside down in the tread grooves. Be sure to check the depth at several spots.