Comparing treadwear on commercial tires between manufacturers is not terribly useful for performance applications since the testing done does not at all resemble what you do with the tires on the racetrack. Treadwear is used by manufacturers to position their product line more for marketing than any objective measure. The intent was to be a more reliable measurement for consumers but once manufacturers were given the control over testing it's become less than useful. Consumers are mislead on this.