power consumption of tyres

this report surveys the work on the rolling resistance of tyres as a preparatory phase in a research programme on heavy goods vehicle tyres. the rolling resistance of a tyre is influenced by a number of parameters principally because of the hysteresis energy loss in the component parts of the tyre due to the delayed response to a stress change caused by the visco-elastic nature of the material. some of the factors which will tend to reduce the level of rolling resistance coefficient are as follows: 1. increase the tyre inflation pressure; 2. change from cross-ply to radial-ply tyre; 3. change from a low resilience material to a higher resilience; 4. increase the tyre temperature; 5. decrease the tyre tread depth; and 6. decrease the vehicle speed. wheel tracking will also affect the rolling resistance, as any mis-alignment will have a component which effectively acts as a retarding force although it is not strictly part of the rolling resistance of the tyre. (a)