Rolling Resistance

The rolling resistance of tires may differ greatly. A nearly 40% difference in rolling resistance transforms into an approximately 6% difference in fuel consumption. Thus, the tire can save both the environment and money. With the current fuel prices, a tire with a more economic rolling resistance can save nearly $500 over a driving distance of 50,000 miles. A wise choice of tires and a careful driving style also help to significantly reduce the CO2 emissions generated while driving.

Rolling resistance refers to the energy consumed in the deformation that takes place when the tire grips the road. This deformation, and the amount of energy it requires, can be regulated with structural and material choices in tire design. Examples of factors that increase energy consumption include the tire temperature, tire pressure, load index and tire wear, as well as air resistance and turbulence depending on the driving speed. Furthermore, a 0.5-millimeter water layer may increase rolling resistance by 50%.

Rolling resistance affects the environment throughout the tire’s useful life. Light rolling corresponds to lower fuel consumption and CO2 emissions. Rolling resistance is measured in terms of a rolling resistance coefficient: the greater the coefficient, the heavier the tire rolls. The average rolling resistance value for contemporary tires varies from 1 to 1.2.

Only 20–30% of the energy contained in fuel can be used to move a vehicle. This energy is used to accelerate and brake, but also to overcome rolling resistance and air resistance.