Tire treads look like an arrangement of horizontal, vertical and diagonal lines cut or channeled into the rubber to create a pattern across the tire. Treadwear can often be detected by a frayed appearance or saw-tooth-like cuts in the edges of the tire pattern.
Tire tread consists of rubber or a rubber composite designed to offer an appropriate amount of traction without degrading or wearing away too quickly. Tire treads consist of grooves, which are designed to channel water away; lugs, or parts of the tire pattern that contact the road; and voids, which define the space between the lugs and enable the lugs to flex and evacuate water.
Treadwear is the measure of how long the tire tread will last before falling below a certain operating standard. This standard is referred to as the treadwear grade, or rating.
Treadwear grade ratings are determined by the Course Monitoring Tire, a standard tire used in manufacturer testing to which all other tires are compared. This test tire is assigned a level of 100 percent -- the highest level possible. A new tire with a tread rating of 100 percent is considered to have a useful lifespan. Tire testing is not regulated and can vary. Check with the manufacturer of your tires to determine details regarding the lifespan of the tire and other tread features.
