1. Standing wave
When the vehicle is running, the tire continuously flexes as a new section of the tread comes into contact with the road surface. Later, when this section leaves the road surface, the pressure of the air inside the tire and the elasticity of the tire attempts to restore the tread and carcass to their original state. At higher vehicle speeds, however, the tire rotates too quickly to allow enough time for this. This process, continually repeated at such short intervals, gives rise to oscillations in the tread. These oscillations, which are referred to as standing waves, continuously propagate around the tire. The majority of the energy locked up in the standing waves is converted into heat, which sharply raises the tire temperature. Under certain circumstance, this heat build-up can even destroy the tire in the space of a few minutes by leading to separation of the tread from the carcass (blowout).
A vehicle skids on a water-covered road if the vehicle speed is too high to allow the tread enough time to remove the water from the road surface so that it can get a firm grip. The reason for this is that, as the vehicle speed increases, the resistance of the water increases accordingly, forcing the tires to “float” on the water’s surface. This phenomenon is known as hydroplaning or aquaplaning.
Do not use a tire with a worn tread. As the tire wears, the tread reaches a point where the tread grooves cannot drain off the water between the tire and the road fast enough to prevent hydroplaning.
Raise the inflation pressure. A higher tire inflation pressure opposes the pressure of the water trying to force itself under the tread and thus delays the onset of hydroplaning.
A higher load accelerates tire wear in much the same way as a reduction in inflation pressure does. The tire also wears more quickly during cornering when the vehicle is heavily loaded because the greater centrifugal force during cornering causes the vehicle to generate greater cornering force, thus generating greater friction between the tire and the road surface.
4. Vehicle speed
The driving and braking forces, the centrifugal force at cornering, and the other forces acting on the tire, increase in proportion to the square of the vehicle speed. Raising the vehicle speed therefore greatly multiplies these forces, increases the friction generated between the tread and the road surface, and thus accelerates tire wear. In addition to these factors, the condition of the road also has a great influence on tire wear: a rough road will obviously cause a tire to wear faster than a smooth road. (2/5)
Tire wear and braking distance
Tire wear does not greatly affect the braking distance on a dry road surface. On a wet road surface, however, the braking distance is considerably longer. Braking performance is poor because the tread pattern has worn down to the point where it cannot drain off the water between the tread and the road surface, leading to hydroplaning.