If my treadwear grade is 400, how long will the tire last?
The best way to understand a treadwear grade is to compare the grade of one tire with another. For instance, a tire with a treadwear grade of 400 might be expected to last twice as long as a tire with a treadwear grade of 200. However, there is no way of accurately predicting how long your tires will last. This is determined not only by tire quality, but also by road surface quality, personal driving habits, tire inflation pressures, wheel alignment and frequency of tire rotation. The treadwear grade is only a reference point to indicate how one tire performs in relative terms to another on the government-controlled treadwear course. It was never intended to project the exact mileage a particular tire might deliver.
