Influence of Tyre Rolling Resistance and Operational Parameters on Vehicle Fuel Efficiency

There has been a persistent demand for Vehicle fuel efficiency improvement, due to rising fuel price and imposition of stricter regulatory norms to curb greenhouse gas emissions. Factors like driving style, vehicle weight, engine, tyre, aerodynamics, weather conditions, etc. affect fuel efficiency. This study focuses on the impact of certain sub-parameters like tyre construction, tyre wear, inflation pressure and driver behavior to establish a correlation between the Rolling Resistance Coefficient (RRC) of a tyre and the fuel efficiency of the vehicle. Tyres with contrasting RRC are considered with multiple drivers and driving conditions while measuring Fuel efficiency using test cycles defined as Constant Speed Test (CST), Mixed Cycle Test (MCT) and Public Road Test (PRT). Fuel consumption sensitivity to driving behavior or driving aggressiveness varies even within expert drivers [1,2]. Reduction in Non-Skid Depth due to tyre wear adversely affects its properties eventually impacting rolling resistance [3]. A deviation from recommended inflation pressure impacts the footprint and subsequently the rolling resistance [4]. The test methodologies incorporated for testing indicated a consistent relation in test results with the different tyregroups. It has been observed that for about 5-6% reduction in RRC of a tyre, 1% improvement in vehicle fuel efficiency is observed in PRT cycle while the impact is inconsequential for CST and MCT. The variation in driving style ranging from aggressive to moderate resulted in a substantial impact on fuel efficiency for PRT and CST while it was minimal for MCT. A swap of inflation pressure from front to rear and vice versa creates a considerable impact on fuel consumption.