Tire Rolling Resistance
Continental takes both driving safety and ecological aspects into consideration when developing new tires.
Rolling resistance is the resistance that occurs due to deformation of the rubber and to friction when a tire rolls on the road. This resistance has a direct impact on a car’s fuel consumption and on CO2 emissions.
The rule of thumb is that approximately 20% of a car's fuel consumption is attributable to its tires.
Therefore, the reduction of rolling resistance is a direct measure to lower CO2 emissions.
The rule of thumb is that 10% less rolling resistance is equal to a 40 kg reduction of CO2 emissions per car per annum (based on a medium-sized car traveling 20,000 km a year)
And yet a high-tech tire must be as balanced as possible in all of its characteristics. If one focuses entirely on improving just one characteristic during tire development, other product characteristics automatically suffer as a result of the interrelated physical processes. There are about 70 conflicting goals in the development of tires. But one of the key conflicts is:
A 10% reduction of rolling resistance causes a 10% deterioration in the tire’s wet braking performance and the braking distance becomes much longer.
The rule of thumb is that 10% less rolling resistance is equal to an 8 m longer braking distance*, which is equal to an impact speed of 35 km/h.
*(ABS braking on a wet road, from 100 km/h to a standstill).
We assign top priority to safety. So a short braking distance, good handling, and superb wet-weather performance must not be neglected in order to reduce the rolling resistance. Thanks to technical innovations (e.g. the use of new rubber compounds, modifications to tire design, and new materials) we have succeeded in lowering the rolling resistance of Continental tires by about one-third in recent years, while significantly improving safety-critical features. Thus softening one of the major conflicts in tire development. Realistically speaking though, it will only be possible to almost halve the rolling resistance within a time frame of the next 30 years.