But for those who have noticed that it does indeed get rather cold in the months before and after Christmas, Continental has some heart warming news: Rolling resistance for winter tyres, contrary to common misconceptions, is no greater than that of their summer counterparts, thanks to the materials used, their low weight and tread design, all of which reduce tyre deformation.
Therefore, says Conti, to put off changing tyres it is a false economy – with the coldest part of the year now quickly drawing in, the braking capacity of winter tyres is markedly better than that of summer tyres. The tyremaker adds that fuel consumption is higher in winter than in the summer is attributable solely to the fact that it takes the engine longer to warm up in low temperatures.
Reducing rolling resistance has long been a main objective in the development of modern winter tyres. Conti says its tyre engineers have focused their attention on the products in the ContiEcoContact range, of which 160 million units have been sold in the past 15 years. They have managed to reduce rolling resistance successively from one model to the next, so that it is now some 20% lower than prior to the launch of the Eco range. Development has now moved on to the third generation model, and the previous virtually irreconcilable development conflicts between "low rolling resistance" and "grip on a wet road surface" have been resolved to a far greater extent.
"As a result of our continued development work, there is no longer any difference between summer and winter tyres in terms of rolling resistance," points out Dr. Burkhard Wies, vice-president, of tire line development at Continental. "In some of our models, the rolling resistance coefficient of around 1.0 cr in winter tyres is even slightly lower than in their summer counterparts." As for higher winter fuel consumption, Dr. Wies explains this cannot be avoided as it is linked to engine warm up time. His advice, therefore, for those wishing to do something good for the environment, is to fit winter tyres and, if at all possible, walk occasionally, despite the poor weather. (Tyres & Accessories/Staffordshire, U.K.)
