Tread depth is an important tool to measure whether a tire is safe to drive on, but that doesn't explain the unusual ...

Pinching pennies. Grooves reveal more of Lincoln's head as tires wear; wet-weather grip declines long before the top is visible. Gauging wear. A tread-depth gauge shows wear more precisely.

bringing it in line with the wear level of the existing tires. You'll have to measure your tires with a tread gauge, and Tire Rack won't wear tires down past the halfway point of about 6/32 of an ...

Determine if it’s time to begin shopping for new tires by placing a quarter, with George Washington’s head facing down, into a tread groove. The top of his head to the edge of a quarter is 4 ...