The rolling resistance coefficient (RRC) data for about 100 models of passenger car radial tires had been determined by following the ISO 28580 test protocol.
Average RRC values are calculated for the three global regions where tires were manufactured and purchased: Americas, Europe and Asia-Pacific. Tire RRC values are assigned into energy efficiency classes based on the regulations of the Commission for the European Union.
Using available 2014 data on the number of light vehicles worldwide, the average distance vehicles are driven each year, and the average fuel economy per vehicle, the potential fuel savings are calculated if tire RRC is reduced changing it into a more energy efficient class.
Corresponding potential savings in CO2 emissions are estimated. Similar data for light vehicle use in the U.S. allows for calculation on potential gasoline savings and estimation of CO2 emission reductions.