To the casual observer all tires look the same. But if you look carefully, you'll find modern tire construction offers a degree of handling, ride comfort, traction, tread wear and fuel economy that far exceeds tires built just a few years ago.
Today there are tire designs that contain up to 200 raw materials as well as a complex architecture of steel belts, textile plies and computer designed tread patterns. Tire manufacturers strive to deliver the most competitive designs in terms of performance and wear.
In 1946 the tire industry was revolutionized by the introduction of the radial tire. A cross section of the radial design is shown above. Today, virtually all tires sold are radials due to their benefits of superior handling, ride quality and wear.
The top layer of the radial casing usually consists of steel belts made up of woven strands of steel cord. Steel belts provide a stable foundation for better tread wear and traction, and also protect the casing against impacts and punctures. Other components may include bead chaffers and cap plies - usually built into performance tires to enhance cornering and stability at high speeds.
The outermost part of the tire, the tread, usually attracts the most attention. The material used is referred to as tread compound, which varies from one tire design to the next. A winter tire, for example, has a compound that provides maximum traction in cold weather. Competition tires, at the other extreme, use a compound designed for very high temperature ranges. The great majority of tires are built with an all season compound that delivers traction in the broad middle range of every day driving conditions. In addition, this compound must deliver good wear; this dual goal of traction and wear remains one of the most challenging design parameters for tire manufacturers.