Tire

Building upon an ancient concept known as "the wheel", the tire is an inflatable rubber covering which sits around the rim of a wheel to make it look pretty. Controversial studies suggest that the addition of tires to wheels provide more grip and stability for the vehicle's driver, but these claims are yet to be proven independently. The modern tire contains over 200 materials, including kevlar, nylon, rubber, and steel. This is why they smell so good when you burn them.