Dunlop launches new SP WinterSport 4D

14^th March 2010, Are, Sweden. Dunlop unveil their latest ultra high performance winter tire today, appropriately in the harsh near-arctic conditions of Northern Sweden where the performance of the tire will be demonstrated against key competitors. The new Dunlop SP WinterSport 4D incorporates a range of innovative new technologies designed to enhance safety and provide the feedback that gives the driver confidence in the wide range of winter conditions.

Designed to excel in all Winter Conditions

Increased Grip in Snow and Ice

The recent harsh winters in Northern Europe have reminded drivers (even in countries where Winter Tires are not required by law) of the benefits of choosing the best tire for the conditions. The Dunlop SP WinterSport 4D derives its name from a new 4D sipe system.

Dr Bernd Loewenhaupt, Director, Consumer Tire Development, explained the technology: “A sipe is an ultra-thin groove in the tread that enhances traction and grip. Compared to its predecessor, we have combined our acclaimed 3D sipe system with a new transversal sipe and created a micro-block that allows better pressure deployment on the road.”

The 3D sipes on the tire tread increase the number of sipes and therefore edges in contact with the road, giving additional braking and acceleration performance.

“On the Dunlop SP WinterSport 4D we add a transversal sipe. This gives additional edge in the lateral direction, ideal for enhanced lateral grip. The combination of both (4D Sipe System) creates an independent micro-block that allows a better pressure deployment in contact with the road, for extra snow handling performance and cornering grip” added Dr Loewenhaupt

The opening of the sipe is determined by traction force. The higher the traction force in circumferential direction, the more the opening. However, the deformation of the tread blocks is reduced by the innovative system of interlocking 3D-sipes.

On the new SP WinterSport 4D tire there is a sawtooth feature on the inside of the blocks for additional deep snow braking performance.

On Ice, the performance of the Dunlop is enhanced by a compound featuring Functionalised Polymers that avoid the symptoms associated with compound hardening at lower temperatures.

Designed to excel in the rain

The Dunlop SP WinterSport 4D is not just an outstanding performer in snowy conditions. For much of Europe, the cold months are characterised by wet roads that never receive the sunlight or temperatures needed to dry them. To perform in these conditions, Dunlop has invested in a combination of unique directional tread design and a dynamic tread compound. “Our tread compound is designed to evacuate water quickly and efficiently by eliminating turbulence in the tread grooves. The compound’s functionalised polymers provide the optimum dynamic stiffness needed at different temperatures. These active ingredients ensure that the Dunlop can deliver best in class grip on wet roads without compromising on snow performance. Our choice and mix of compound is tailored to maximise snow and wet performance – whilst still allowing an improvement in rolling resistance, benefiting fuel economy” added Dr Loewenhaupt.

Engineered for performance and road feedback

Dunlop ultra-high performance tires are famed for their road feedback and enhanced steering feel. This is one of the reasons why Dunlop is chosen by performance car drivers, tuning companies and prestige, high performance OEMs such as BMW, Audi, Mercedes Benz, and Jaguar. It is therefore important to Dunlop that a winter tire should share these same qualities. To achieve high levels of steering response, the Dunlop SP WinterSport 4D features an interlocking mechanism on its sipe system. Under braking and heavy cornering conditions the blocks lock together giving a steering and braking response more akin to a dry weather summer tire.

Low weight means more performance – and efficiency

Dunlop are race winners in the Le Mans series, where tire weight optimisation is a relentless focus for engineers to improve performance and the efficiency of cars in endurance racing. “Dunlop has applied the same focus to the SP WinterSport 4D, improving rolling resistance by 11% versus its predecessor, thanks in part to the functionalised polymers in our tread compound that reduce rolling resistance, whilst enhancing wet and snow performance. This, combined with a weight reduction, means the tire requires less power from the engine to overcome the rolling resistance. When it comes to the effect of weight on the performance of a tire, in this case, less is more!” added Dr Loewenhaupt.

Building on proven success

The latest Dunlop is designed to raise the bar still higher, as its predecessor (SP WinterSport 3D) was a prolific winner of recommendations in international independent tire tests organised by the world’s motoring press. For example, as recently as last year, the SP WinterSport 3D reinforced its reputation with accolades in the ADAC Motorwelt/ÖAMTC, AutoBild Sportscars, Stiftung Warentest and AutoBild Allrad comparison tire tests.

However, for Dunlop, being First is not enough. Dunlop has a winning mentality evidenced by its success in International Motorsport, and this mindset means the company are constantly developing new tire technologies to enhance performance and driving pleasure. The result is the new Dunlop SP WinterSport 4D.

Wide range of sizes to suit most performance cars

The Dunlop SP WinterSport 4D is available in 37 variants, from 195/65R16 to 255/35R19 covering more than 8 out of 10 cars in the high performance tire market.