When was the last time you took a close look at your tires? The tires are the only contact the vehicle has with the road. Clearly the performance of the car or truck is dependent upon quality tires in good condition. Before you hop in your car and drive off the next time, take a closer look at the rubber that meets the road; your life could depend upon it.
Look in the grooves between the tire treads for raised patches of rubber called wear bars. These 2/32” tall patches will help you identify a worn out tire. When the wear bars are flush with the tread it indicates that tread depth has reached the legal minimum of 2/32”.
If tires do not have wear bars, traditionally it was recommended to place a US penny in the groove with Lincoln’s head down. If the tread is at or beyond the top of Lincoln's head you have at least 3/32” of tread left. However, the performance of the tire will be far less than when the tire was new, especially in wet road conditions. Check out the resource from TireRack.com to learn more about performance and tread depth.
Tread depth is important, but even wear is also vital to safe performance. Improper inflation can lead to rounded edges on the tire inside, outside, or center. Uneven wear between front and rear tires indicates the need for more frequent tire rotation. A chop or stair-step wear pattern could indicate worn shocks and excessive wear on the inside or outside of the tread could indicate the need for alignment.
Carefully check each tire for punctures, nails, scuffs, and weather cracking. Repair or replace as necessary. If you are driving a commercial vehicle the standards for tire wear are more conservative. For example, front tires on trucks and busses must have at least 4/32” of tread depth. Check out the Federal Motor Carrier Safety Administration standards for more information.