Rolling resistance refers to the force required to move the tyre. Various factors affect rolling resistance. It depends on the type of tyre, on its width, tread pattern and the material composition of its tread. The loading of the car, too and, in particular, the air pressure greatly affect the rolling resistance. This is why it is important to check the air pressure regularly. In addition, a tyre with too little air pressure is subject to higher wear and the risk of failure increases drastically.
If the rolling resistance is reduced, for example, by ten per cent, this leads to fuel savings of two per cent.