Latest Nokian WR aimed at growing Central European market

According to Nokian Tyres, around 50 million winter passenger car tyres were sold in Central Europe in 2010 – 16 per cent more than the previous year. The Finnish tyre maker’s latest product – the third generation of its ‘WR’ series – is targeted directly at this growing market. This time round two versions of the Nokian WR, each with its own tread pattern, are available: the economy focused WR D3 is intended for medium-sized and small family cars, while the WR A3 is optimised for larger and more powerful vehicles and places a stronger emphasis on driving response at higher speeds.

Both incarnations of the new WR are manufactured using what Nokian calls ‘Cryogenic Canola Compound’, a combination of natural rubber, silica and canola oil intended to optimise winter grip, wet grip and wear resistance in varying temperatures. This full silica compound contains a so-called cryo silane, which Nokian says enhances the functionality of the rubber mix, while the canola oil used is said to provide higher resistance to tearing while improving snow and ice grip. The high silica content offers the usual rolling resistance benefits. “We utilised our top expertise and knowledge of all types of winter conditions. Thanks to nanotechnology, new materials and innovations, as well as our modern production technology, we are able to provide drivers with tyres that have first-class grip and handling properties,” commented Teppo Huovila, Nokian Tyres’ vice president, R&D.

 Nokian WR D3

 
Studies have shown that slush is even more dangerous for drivers than ice or aquaplaning – Nokian reports the risk of fatal accidents is more than four times higher on slush than on dry surfaces. To handle this hazard Nokian says it has implemented “new solutions to actively prevent slush planning” in the WR D3’s directional tread pattern. “We further enhanced the tyre’s resistance against aquaplaning and slush planing by applying a slanting, staggered front edge of tread blocks,” Huovila explained. “This new innovation is called Slush Blower, because it actually blows water and slush away from the tyre grooves. The polished grooves also speed up the removal flow of water and slush.”

 Nokian reports that computer and thermographic camera simulations were utilised to find the optimal symmetric tread design. The siping employed does not break the edge of the block, a quality the tyre maker says “ensures excellent grip and enables the framed block to maintain its rigidity.” This so-called ‘Cool Touch Design’ is also intended to minimise the friction and heat emission caused by unnecessary sipe movement. “The tyre rolls easily and supports effortless, energy-saving motion with its low rolling resistance,” states Nokian in a press release. “Thanks to the uniform tread structure, the Nokian WR D3 responds to steering movements quickly and has a calm, quiet contact with the road.”

Nokian WR A3
 
Tests performed by Nokian Tyres showed an asymmetrical, open-centre tread pattern to be the best means of combining sturdiness with responsiveness, especially for tyres used at high speeds. The WR A3 thus features an asymmetrical inside-outside tread pattern that the tyre maker says enables reliable grip without compromising high-speed driving properties. The inner shoulder design is intended to enhance the removal of water and slush. Sturdiness is reported to be enhanced by the inclusion of ‘3D Lock Sipes’ on the WR A3. Nokian says these lock the outer shoulder area’s blocks together during contact with the road. The blocks cannot move when driving; instead, they support each other, eliminating unnecessary sipe movement and thereby lowering the amount of heat emitted from the tyre.

“A stable driving response is emphasised at higher speeds. This has been a particular focus in the development of the Nokian WR A3,” Huovila shared. “It has a Nanobase support layer at the bottom of its strong cap & base structure. The smaller molecular structure enabled by nanotechnology improves the tyre’s steering properties and control when driving in corners, changing lanes and dodging. The tyre has exemplary control properties in extreme situations both on gripping and slippery surfaces. Thanks to its innovative structure, the Nokian WR A3 is safe and accurate even in demanding conditions.”  The Nanobase structure is said to also reduce the tyre’s heat emission and, consequently, lower its rolling resistance.

 The sides of the longitudinal ribs on the WR A3 feature semi-round cavities that resemble the dimples on a golf ball, and Nokian says these cool the tyre it increase its safety at high speeds. This feature, called Silent Groove Design, is also said to reduce drag and lower fuel consumption while minimising the vehicle’s inside and pass-by noise: the cavities cut off the noise stimuli generated by air flow and prevent the generation of a whistling noise. Another noise reduction feature on both the WR A3 and WR D3 is Nokian’s Silent Sidewall Technology, a strip on the sidewall designed to filter noise and vibration emitted from the road surface through the tyre tread and relay it to the bead area in order to reduce noise levels heard inside the vehicle.

The latest generation Nokian WR is available in a range of sizes between 13 and 20-inches and T to W speed ratings. Aftermarket supply will begin in autumn 2011.