Tire hardness can be a critical factor in setting up a race car. A tire that's too hard may sacrifice traction, while a tire that's too soft may give great traction but wear too quickly, and an unmatched set of tires may result in an ill handling car. To properly set up a car, a measure of tire hardness is necessary, and the easiest and most cost-effective way to obtain such a measure is to use a durometer.