Tread Compound Effects in Tire Traction

Changes in practical compounds have given appreciable improvements in friction on wet surfaces but only minor improvements on dry or icy surfaces. The wet skid resistance of a tread compound is determined primarily by its hardness and hysteresis. Improvements in skid resistance are usually made with a concurrent, predictable, loss in wear resistance for practical compounds. Tire materials research devotes its efforts to development of factors which will permit gains in traction with minimal losses in wear. A typical tire compound is examined for the effects of the ingredients on improvements in wet traction, i.e., raising the glass transition temperature of the polymer or the extender oil, increasing the fineness of the carbon black, and lowering the level of curatives.