The bars become flush with surrounding tread when wear reduces a groove's depth to 2/32 of an inch ... about 3 to 4 mph slower than the full-tread tires. As the chart in All-season-tire wear ...
The Family Handyman on MSN6mon
How to Check Tire Tread
What Is the Optimal Tread for a Tire? The minimum legal limit for tire tread depth is 2/32 of inch, but it's best not to wait ...