Treadwear rating is a number stamped on the tire sidewall that relates to the expected wear of the tire. It is a relative score given to a tire as an estimate of its longevity, and it is not a projected estimate of mileage or tread life. Treadwear refers to the expected life of a tire, and the treadwear rating is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. The treadwear rating is determined by the manufacturer, and it is based on how well the tire stood up in tests against a “control set” of tires after being driven 7,200 miles on a government test track. The higher the treadwear rating, the slower the tire wears compared to the control tire. However, it is important to note that a good treadwear rating depends on the tread type, and there are many factors that affect a tire’s expected life in terms of mileage.