The importance of checking for tire wear!

U.S. coins can be substituted for a tire tread depth gauge as tires wear to the critical final few 32nds of an inch of their remaining tread depth.

Place a penny into several tread grooves across the tire. If part of Lincoln’s head is always covered by the thread then you are still in good shape. You should have around 2/32” of tread depth left. 

Place a quarter into several thread grooves across the tire. Similar to what you did with the penny. If part of Washington’s head is always covered by the tread, then you have 4/32” of tread depth remaining.

According to most states' laws, tires are legally worn out when they have worn down to 2/32" of remaining tread depth. To help warn drivers that their tires have reached that point, tires sold in North America are required to have indicators molded into their tread design called "wear bars" which run across their tread pattern from their outside shoulder to inside shoulder. Wear bars are designed to visually connect the elements of the tire's tread pattern and warn drivers when their tires no longer meet minimum tread depth requirements.