Vredestein Releases 186mph Winter Tyre

It is just over a year since Dutch manufacturer Vredestein was acquired by Apollo Tyres and adopted a greater focus towards high performance tyres and products for top-end vehicles, and at the Reifen 2010 exhibition in Essen, Germany the company presented the first major addition its product portfolio since these significant events took place. Known as the Wintrac Nextreme, the high performance cold weather tyre is the second winter tyre ever to be developed in collaboration with Italian design house Giugiaro, whom Vredestein has worked together with for more than a decade.

According to Vredestein, both stylistic considerations and functionality were of great importance during the Wintrac Nextreme’s design; the manufacturer refers to the tyre as an “ideal combination” of these two qualities, and states that “the tyre has an attractive, flowing design while simultaneously guaranteeing outstanding performance in even the most extreme winter conditions.” As would be expected, the Wintrac Nextreme already complies with the European regulation for wet grip and noise that come into force in 2012, and Vredestein adds that the level of rolling resistance it generates will entitle it to wear the “green” label to be introduced as part the upcoming labelling system.

This successor to the Wintrac xtreme, says Vredestein, is not only strong in winter conditions, but also responds exceptionally accurately on wet and dry surfaces. The tyre’s tread is a non-directional, asymmetrical pattern that the manufacturer describes as featuring a higher “air count” at the point where water dispersion matters the most – on the inside of the tread. This is achieved, Vredestein explains, by making the lateral grooves on the inside of the tyre wider than the lateral grooves on the outside, combined with two longitudinal gulleys on the inside. The Vredestein engineers introduced this feature to ensure the tyre can drain off water and slush quickly and efficiently, minimising the risk of aquaplaning, while the stable outer shoulder is intended to ensure a very high level of steering precision and excellent driving performance.

The tread of the Wintrac Nextreme features something  Vredestein calls “Sophisticated Sipe Design” (SSD). This refers to the pattern in which the sipes are arranged: In the wide central section, the sipes are 0.6mm thick and positioned at right angles to the direction of travel. As Vredestein explains, this provides extra traction and grip in the most important part of the contact area for a snowy road. The sipes on the inner and outer shoulder are 0.5mm thick, positioned diagonally and zigzag-shaped, which is said to be particularly beneficial on bends due to the greater block rigidity. Functionally speaking, the sipes on the outer shoulder are also shorter than the ones on the inner shoulder. This gives greater block rigidity and hence more stability when cornering at speed. The zigzag pattern of the sipes is continued in the lateral grooves so that the increased axial grip increases road-holding safety on very slippery surfaces.

A further tread element is the Interlocking Tread Bridge (ITB), which consists of a longitudinal rib with zigzag lateral grooves and sipes alongside the central section. This rib contains connections which intentionally interrupt the open tread pattern and hence act as a bridge. The ITB, Vredestein comments, gives the tread blocks of the Wintrac Nextreme more stability and the tyre greater steering precision. It is also designed to ensure a regular pattern of wear to boost the tyre’s durability and keep noise at low levels during its lifespan.

The tread compound, which was specially developed for the Wintrac Nextreme, is PCA-free. Its polymer-to-filler ratio produces an adaptive winter tread compound, Vredestein adds; one that is relatively soft at low temperatures in order to provide good grip in winter conditions, while at warmer temperatures it is hard enough to make the tyre adequately stable at higher speeds. The compound is produced using the newly developed ‘Twin-Boost’ system, in which a double mixing speed boost is applied. During this mixing cycle a total of three polymers, two types of fillers (silica and soot) and 11 other raw materials are processed into a UHP winter tread compound.

As the manufacturer points out, the Wintrac Nextreme is designed to have very even surface pressure distribution – which is crucial for the tyre’s performance. The right combination of tyre structure and tread shape gives a contact footprint that combats aquaplaning while at the same time promoting a “flat” wear pattern. Such a footprint is also said to allow for good handling behaviour and steering precision.. The tyre’s characteristics at high speeds can be attributed to the endless strip-wound Nylon Overhead, which consists of two layers. Because of this, says Vredestein, surface pressure distribution is and remains ideal, at both low and high speeds.

The Wintrac Nextreme is available in three speed ratings: V, W and – offered in a winter tyre for the very first time – Y, the last of which is suitable for speeds of up to 186mph (300km/h). The range covers fitments for 16 to 21-inch rim diameters. Thus the tyre fits perfectly into the ‘Premium Styling’ concept that Vredestein introduced at the end of 2009 for people who want to drive their high performance car in both the summer and winter, without having to switch over to winter tyres with a smaller rim diameter and a lower speed code.

Design of the new UHP tyre was performed by Giugiaro, the legendary Italian designer proclaimed ‘Car Designer of the Century’ in 1999. The flowing, fan-shaped tread pattern has some aspects in common with the Vredestein Ultrac Sessanta, a Giugiaro-designed summer tyre. But the Wintrac Nextreme represents the first occasion that Giugiaro has designed a complete tyre in which the tread is integrated with the sidewall design to form a single whole – something that Vredestein says is completely new in the tyre industry. “The supple, undulating style hallmarks of the tread form a raw and industrial contrast with the sipes and tread blocks, which primarily radiate grip, solidity and strength and continue seamlessly into the sidewall design,” states the manufacturer. Yet Vredestein makes it clear that these aesthetic considerations do not detract from the essence of a car tyre: it is and remains a safety product.

Currently the Wintrac Nextreme is available in 11 sizes and is also available in an SUV version consisting of seven sizes. Compared with the normal Wintrac Nextreme, the Wintrac Nextreme SUV has a double rayon carcass layer and an extra robust belt, giving the tyre a high load-bearing capacity. The extra wide tread provides good road-holding and more stability, Vredestein reports, and the tyre is suitable for off-road driving.