Latest Generation Michelin Alpin a Wet Winter Specialist
In 2010 Michelin launched the fourth generation of its Alpin winter tyre into the replacement market. The Alpin A4, released in sizes to fit a wide range of vehicles from city cars through to MPVs and saloons, is intended for European markets where winter roads are generally wet – around 80 per cent of the time – and less often icy or snow-covered. In other words, the latest Alpin is a tyre specifically designed for the winter conditions we experience in spades.
As would be expected, this latest generation Alpin delivers superior performance than the tyre it replaces. Tests conducted earlier in the year by TÜV SÜD Automotive using size 195/65 R15 T and 205/55 R16 H tyres showed the Alpin A4 to deliver ten per cent better grip on icy or snow-covered surfaces and offer five per cent shorter braking distances on wet, icy or snow-covered surfaces. The independent technical services firm’s tests also indicate the new Alpin (again tested in sizes 195/65 R15 T and 205/55 R16 H) can be driven up to 35 per cent further than its leading major brand competitors, namely the Bridgestone Blizzak LM30, Continental ContiWinterContact TS 830, Dunlop SP Wintersport 3D and the Goodyear Ultra Grip 7+. This, Michelin points out, equates to an extra winter’s driving.
Michelin states that its latest winter tyre offers a good illustration of the company’s strategy, which is never to sacrifice one performance feature for another. This means performance in several different areas must be simultaneously improved. This typically presents a number of technical problems, yet Michelin believes it has resolved these with the Alpin A4. To achieve this performance balance, the new tyre integrates a number of technologies, some of which have been derived from tyres developed for the severe winter road conditions experienced in Scandinavia, such as the Michelin X-Ice North, which was introduced in 2009.
A technology taken from this Nordic tyre is one of two Michelin says forms the basis of the ‘integrated solution’ that enables the new Alpin to “deliver unrivalled safety performance while also enabling cost-savings through longer tread life and low fuel consumption.” Specifically, Michelin made adjustments to the tread developed for the X-Ice North. Called Full Active Tread, Michelin says the new tread features five distinct technical solutions. The second technology is a Michelin-developed rubber compound containing sunflower oil, known as Helio Compound+. The French manufacturer says this compound not only enhances grip on winter roads, it also helps to increase mileage and ensure low fuel consumption.
Full Active Tread
Michelin reminds us that a tyre’s tread is designed to meet one simple objective: every square millimetre of the contact patch must actively help to deliver superior grip. This is reflected in braking, road holding, stability and handling qualities. To ensure the latest generation Alpin delivers optimal overall performance, Michelin’s research and development teams worked simultaneously on five technical solutions, Michelin explains these as follows:
A continuous contour tread. The tyre features a unique tread design that delivers excellent lateral and longitudinal grip thanks to a wider contact patch. At the same time, handling is also improved due to more uniform contact areas and a more gradual transfer of pressure from one tread block to another.
A greater number of patterns. The new Michelin Alpin comprises 71 different tread patterns on the tyre surface – compared with 59 for the same-size version of the previous model – thereby improving snow traction. That’s because the greater number of patterns create a caterpillar-like effect on snow-covered surfaces.
Fifty per cent more ridges and high sipe density. The new Michelin Alpin has 50 per cent more ridges than the previous-generation tyre. These additional ridges enhance the tyre’s claw-like grip on slippery surfaces.
StabiliGrip sipes, with 3D technology. At the same time, Michelin has developed its own unique sipes. Designed in three dimensions, they increase the stability of tread blocks – and thus of the tyre itself. And because they are numerous, they improve vehicle stability. The sipes on the all-new Michelin Alpin are crossed, with the combination of vertical and lateral undulations making the tread blocks stiffer. The sipes lock into each other to add rigidity to the blocks. As a result, stability is enhanced when the tyre is in contact with the road, regardless of the forces to which it is subject: longitudinal force when braking or accelerating and lateral force when cornering. This in turn improves steering precision.
A self-cleaning tread. The new Michelin Alpin features a self-cleaning tread capable of eliminating snow, slush and water that collects between the blocks. Its V-shape design with lateral grooves extending to the shoulders helps to evacuate water and snow towards the tyre’s outer edges.
More commonly found in the kitchen pantry than the tyre developer’s workbench, sunflower oil forms a key ingredient in the rubber compound utilised in the Alpin A4. Mixed with silica to produce what Michelin calls its ‘Helio Compound+’, this new formula is said to enhance performance in four areas: the rubber’s elasticity is maintained at low temperatures, thereby providing better grip on winter roads, tread block rigidity is stabilised throughout the tyre’s life, thus ensuring long-term performance; Mileage is increased; and fuel consumption is reduced as the tyre heats more slowly, resulting in less energy loss.
Upon launching the new generation Alpin, Michelin stated it is committed not only to quickly renewing all its tyre lines, but also to streamlining its portfolio. It says that in its first year on the market, the Alpin will be made available in 17 sizes (seven 15-inch sizes, nine 16-inch sizes and one 17-inch size) that exist in a total of 35 versions, each corresponding to a specific speed rating and load rating. Thus the Michelin Alpin range can equip more than two-thirds of new vehicles in 2010.