Tire-tread life depends on variables that are not easily duplicated for testing
More customers shop for tires on the basis of miles of tread life per dollar than any other consideration. Manufacturers are well aware of this, so they allocate a large portion of their development budgets to the various aspects of treadwear.
A surprising number of variables, both tire-related and test-condition related, influence wear. Sorting them out to develop a tire that offers optimum wear, while maintaining other properties at acceptable levels, is a formidable task. The first requirement is a method for measuring treadwear. This can be used to learn how materials and constructions affect wear.
Treadwear is evaluated from progressive measurements of either tire weight or groove depths during road tests. The weight-loss method has two major drawbacks. First, a wear-out point is hard to establish, and second, the weight of unabraded portions of the tire may not remain constant. In one test where miniature wheels were pulled behind a …