Central Europe's newest winter tire from Nokian Tyres plc, the WR D4, offers wet grip for passenger cars in the EU tire label's best A cless.
The Nokian WR D4 features focused innovations: The Nokian block optimized siping and twin trac silica offer controlled handling and firm grip for extreme conditions. The size selection of the Nokian WR D4 covers sizes from 14 to 20 inches, with speed ratings from Q (160 km/h) to W (270 km/h). The versatile selection offers exact sizes for sporty rides as well as modern electric vehicles, the company says. The special products in the selection employ Flat Run technology, and many products are marked XL for the highest possible load capacity in a passenger car tire.
It will be available to consumers in the autumn of 2015.
The Nokian WR D4 is created for varying weather. It is an eco-friendly quality tire that masters the changing conditions and represents the new generation that follows the Nokian WR D3, the winner of multiple comparison tests in motoring magazines.
The Nokian WR D4 is a product whose structures and rubber compounds were fine-tuned. The unique slushplaning test method available on the Nokia test track allowed to optimize the slush properties of the tire. The research was supplemented by testing in the arctic conditions of Nokian Tyres' Testing Center in Ivalo, Lapland.
The Nokian WR D4 is a genuine winter tyre that steers in a balanced manner and grips firmly in real winter weather, that is, when driving in snow and slush. Years of work by Nokian Tyres and thousands of kilometres of winter testing all tell the same story: a directional tread pattern is the ideal choice for varying winter conditions.
Each tread block and sipe has a specific role, which gives drivers the ultimate safety accessory that works reliably and predictably on wet roads, snow and ice alike, says Product Development Manager Olli Seppälä.
Winter grip in slippery weather and the precise driving feel are maximized by the new tread compound and the block optimized siping used in the tread pattern.
The center area is dominated by the steering precision rib that can be felt in the steering response on bare roads. The sipes of the center rib do not run across its entire width, which improves precision and promotes controlled handling. The small, heavily siped tread blocks on both sides of the center rib are siped so that every other sipe is attached on the left and every other on the right. The snow performance blocks are split into groups of three and improve grip on snow, and also are supported by raising the bottom of the groove. This improves the rigidity of the tread pattern and results in better handling, Seppälä says.
The stiff handling blocks have heavy sipes to improve traction. They become shallower when moving toward the shoulder from the center. This design improves grip on snow as well as the driving feel required for cornering and lane changes. An aggressive activator sipe that is used to boost the operation of the shoulder block during acceleration and braking, when grip is needed the most, is located in the middle of the shoulder blocks.
The Nokian WR D4 actively fights aquaplaning and slushplaning with the slush blower innovation. The polished grooves also facilitate the removal of water and slush.
The deep snow booster design ensures grip during heavy cornering and while driving in deep snow. The jagged chamfers on the sides of the shoulder blocks grip the surface in a controlled manner, enabling additional grip.
The tread compound of the WR D4 combines the Nokian Hakkapeliitta rubber compound designed for the demanding and cold northern winter with a silica-based compound that provides excellent performance in milder weather. The end result is the Nokian twin trac silica rubber compound, which contains natural rubber, silica and canola oil.
This compound also improves driving stability and wear resistance. The large amounts of natural rubber and canola oil in the new rubber compound ensure that the excellent winter grip properties remain the same even as temperatures change and the kilometres add up. The canola oil added to the compound allows the silica and natural rubber to work together, improving the ice grip and tear strength of the tread compound. Tear strength makes the tyre extremely resistant to wear, impacts and punctures.
In addition to safety, driving comfort is also an essential part of a positive driving experience. The tread structure allows the Nokian WR D4 to react quickly to steering, while it maintains calm and silent road contact. Nokian silent sidewall technology improves driving comfort and reduces the noise level inside the vehicle.
