Fundamentals of rolling resistance

Increasing pressure over the last three decades to improve vehicle fuel economy and decrease emissions along with a strong sense of environmental stewardship has driven the tire and rubber industries to reduce tire rolling resistance. This has been accomplished while simultaneously improving other aspects of tire performance dramatically. Reductions in rolling resistance of 50% relative to 1980 levels have been realized, and efforts continue to decrease rolling resistance further. Laboratory measurement and empirical modeling of rolling, resistance behavior have evolved substantially, and the tire industry can characterize,a tire's rolling resistance with great precision and accuracy. Rolling resistance behavior is quite complex, and nearly all conceivable operating conditions have a measurable effect. The effect of each parameter has received considerable attention in the archival literature, and this review highlights the conclusions of these studies. One of the most powerful tools available to the tire industry is numerical modeling. Combined with accurate dynamic material property measurements, finite element models have provided designers with a tool to understand the behavior of each rubber product and optimize tire construction and material properties to minimize rolling resistance. However, with the current level of understanding and optimization of rolling resistance, substantial breakthroughs in the areas of material development and tire construction are needed to achieve further rolling resistance reductions.