Tire Tread Inspection
While you are checking the air pressure on each tire, visually inspect the tire’s tread and sidewall for signs of wear and road debris that may have penetrated your tire.
Tires depend on good tread condition to maintain traction and to shed water on wet roads. Tread depth should be checked for excessive and uneven wear. Measure tire tread with a depth gauge (available at most parts stores) or a small ruler that has 1/16” gradations. Although it is not as accurate, you also can check tread depth by placing a penny in the tread of the tire. Insert the penny upside-down (inserting President Lincoln’s head into the tire’s tread). If President Lincoln’s entire head is showing, it is time to replace your tires.
Take measurements in three locations across the tire’s tread: (1) outer edge, (2) center, and (3) inside edge. The more tread the tire has remaining, the higher the reading will be. Uneven readings indicate improper tire inflation or the need for a wheel alignment. At 3/32 of an inch, it is time to shop for new tires. At 2/32 (1/16) of an inch, the tread wear has reached its legal limit in most states..
You also may see wear indicators (thin bald strips) revealed across two or more treads. This indicates that the tires have worn to an unsafe tread level, and should be replaced.