In designing its latest eco tire range, Continental AG was influenced to a large extent by the changing requirements of its OE customers. 
As Alexander Luhrs, head of Continental’s press and public relations for passenger and light truck tires, explained at the recent ContiTechnikForum held in Portugal, "the requirements for tire development are in a very dynamic state." This especially applies to rolling resistance optimized products. "Car manufacturers need to reduce CO2 emissions. This means they ask us and our competition to come up with new solutions in this regard."
Thus, reducing rolling resistance was the main focus when developing the ContiEcoContact 5. “This (reducing rolling resistance) is not new, but the level that is requested is new,” Lührs noted, adding that in comparison to the new product, “the tires we are now currently selling are not eco tires. They are not optimized for rolling resistance; they are good, but as you are used to from Continental, they are also designed to have best safety properties.”
Despite a stronger focus on rolling resistance optimization this focus on safety of course does not change in the EcoContact 5, Lührs added. So how effective has Continental’s focus on reducing rolling resistance been? The company reports a 20% reduction in comparison with its previous model the ContiEcoContact 3, while at the same time mileage performance has improved by 12%. As Continental tire developer Christian Strübel explained, modifications to various zones of the tire – the ‘grip’ zone, the ‘load’ zone, the ‘flexing’ zone and the ‘rigid’ zone – contributed to this overall rolling resistance reduction. The compound used and tread pattern featured in the grip zone are said to have contributed 2% to this reduction. Modified polymer chains within the compound bond the silicates contained within even more firmly into the formula, Strübel elaborated, thereby reducing the chemical components’ heat-generating movement.
The result of this is that rolling resistance could be cut while shortening braking distances in comparison with the previous model. The compound used in the load zone is said to have added a further four per cent to the total reduction in rolling resistance, while the sidewall compound in the flexing zone and the bead area compound in the rigid zone reportedly contributed two and four per cent towards this figure respectively.As for the tread pattern itself, Strübel stated that rolling resistance has been reduced through the use of a very flat contour to reduce tread deformation in the contact patch area. “With a flatter contour the belts below the contour are also more flat and this leads to less deformation, less belt movement during rotation,” he added.
To reduce contact patch tread deformation, Conti’s tire developers incorporated extra-thin sipes into the tread lugs. These sipes work like windscreen wipers on wet roads, destroying the film of water when the lugs meet the road and thereby keeping braking distances short. And if these sipes are extra fine in their design, the tread lugs are not compressed during driving, so less energy is lost. At the same time the edges of the tread lugs remain stable and can thus transmit more braking energy – fulfilling a further pre-condition for low rolling resistance.The first sizes in the ContiEcoContact 5 range are already available, but in a departure from standard practice the first dimensions on offer are not the most popular fitments. “In view of the somewhat curious current market situation in which demand for summer tyres is significantly higher than we anticipated one or two years ago, we are producing our established products to satisfy this demand and therefore are not entering the market at full steam with the EcoContact 5,” explained Lührs.
Thus the new tire is initially being offered in 15 sizes for 14- to 16-inch wheel diameters, in speed ratings V (up to 149mph/240 km/h), W (up to 168mph/270 km/h) and Y (up to 186mph/300 km/h). There was no word when or if the tire will be released in North America. (Tyres & Accessories)
