New and Improved
There are two types of European winter: the winter we know and grumble about, with coats, scarves and the heating cranked up a few notches – and then there’s the mind-shatteringly cold northern winter, an environment so unforgiving that even the careless act of touching a metal surface with an ungloved hand may result in the loss of a few layers of skin. So with two vastly different definitions of winter existing within the one region, it makes sense for a tyre manufacturer to recognise this distinction when developing a winter tyre range. Michelin has done exactly this, and offers different winter products in different markets. In Scandinavia and Russia the tyremaker sells products like the Latitude X-Ice North, a studded, blocky, heavily siped tyre designed to tackle severe Nordic conditions. But such a tyre would obviously be ridiculously excessive for a shopping trip to the high street or commuting on the M25, so for our milder, yet deceptively hazardous winters, Michelin offers a more suitable range.
A new product for 2006, the Michelin Latitude Alpin is designed for compact SUVs and crossovers. When the team at Michelin set out to develop a successor to the highly regarded 4×4 Alpin, the aim was to further reduce braking distance and deliver superior traction while maintaining performance levels throughout the tyre’s extended life. A further goal was to reduce the tyre’s environmental footprint (and decrease total cost of ownership) by creating a product capable of higher mileages.
The power output of 4×4 vehicles has progressively grown since they first found favour as a means of transport for the school run and commute to work, thus maintaining safe braking on wet roads during sub 7°C temperatures is today more of a challenge than ever. For this reason Michelin has felt it necessary to progress the Latitude Alpin’s wet surface braking ability one step further than that offered by its predecessor. The French manufacturer reports that the Latitude Alpin’s braking distance from 80 km/h on a cold, wet road – according to in-house tests – is 37 metres, 4 metres less than that of a competing brand. Michelin did not disclose the precise competitor tyre used in the test but indicated that the tyre in question was the product it considers the Latitude Alpin’s main rival. According to the same test results, when a vehicle fitted with Michelin Latitude Alpin tyres has come to a complete stop, a vehicle using the competitor’s tyres is still travelling at 25 km/h.
The high centre of gravity and weight of a 4×4 must be taken into account when designing a tyre that provides good stopping abilities on snow covered surfaces; delivering sufficient grip on slippery roads is, for the above reasons, more of a challenge than is the case for passenger cars. Michelin have made improvements in this area and report that the Latitude Alpin shows significant improvement when braking on snow compared with the model it replaces. In-house tests also show that the tyre’s braking distance from 50 km/h on a snow-covered road is 24 metres, 4 metres less than its main rival. The herringbone tread design employed in the Latitude Alpin maximises the number of ridges and sipes, providing extra bite for braking and traction, without compromising the lateral stiffness necessary for handling through corners.
Traction is still one of the major concerns for owners of four-wheel drive vehicles, no matter what type of surface they are on. Of course, the full traction potential of any vehicle depends on the performance of its tyres. Improving on the Michelin 4×4 Alpin’s already solid snow traction performance was an ambitious objective for the Michelin designers, however they are confident the Latitude Alpin meets all targets they set themselves. Sipes are present not only in the tyre’s tread, but also on the tyre shoulders. The shoulder sipes cut through deep snow to help clear the road and give the tyre extra grip.
Nine sizes of Latitude Alpin have been available throughout 2007, and Michelin report that two new sizes will be added during the year and another seven in 2008.
To meet the needs of the expanding winter and cold-weather tyre market Michelin last year released the third generation of its popular Alpin. Designed to fit the majority of saloons and hatchbacks, this tyre (according to tests) reduces wet braking distances by up to six metres at 40mph compared with an equivalent summer tyre. The Alpin’s compound retains its flexibility even at extremely low temperatures and is able to grip cold, wet roads thanks to a system of micro-distortions in the rubber that adhere to the tiniest irregularities in the road’s surface. This is aided in heavy rain by wide central and transversal channels that expel standing water and allow the tread to grip the road surface. Curved linear sipes allow the Alpin to grip extremely well on snow, and on ice these sipes also cut through the surface film of water to provide high levels of grip on this difficult surface.
When the weather turns dry, Michelin’s Bi-Directional Sipe System (BDS System) of locking tread blocks resists distortion, the cause of the floating sensation and lack of turn-in response normally associated with winter tyres.
Further evidence of the Alpin’s performance is shown by the fact that for three consecutive years it has obtained the top ‘3 star’ highly recommended notation in the ADAC (German automobile club) winter tyre tests. Intended for family vehicles and compact passenger cars the Michelin Alpin is ‘T’ rated and is currently available in 30 sizes, for wheel diameters from 13inch to 16inch, covering more than 50 per cent of the winter tyre market.
The Pilot Alpin is Michelin’s high performance cold weather tyre, and the tyremaker is confident it sets new standards of winter and cold-weather driving performance and safety, whatever the road conditions.
On wet roads a new generation rubber compound used in the current Pilot Alpin reduces braking distance by up to two metres compared with the first generation tyre. This is due to the compound allowing micro-deformations of the rubber that provide contact with every part of the wet road surface and increase grip, even at low temperatures. Another advantage of the new silica based rubber compound used in the Pilot Alpin is that, when combined with the tyre’s new casing structure, it reduces rolling resistance and offers up to a five per cent reduction in fuel consumption compared with the previous Pilot Alpin.
In dry conditions the Pilot Sport derived casing ensures first-rate handling and grip, and the sipes’ self-locking action increases tread rigidity for improved steering response in corners and when changing lanes at motorway speeds. And on icy roads the braking distance of the latest Pilot Alpin is one metre less than that of its predecessor thanks to a new sipe structure. The sipe length has been increased by up to 40 per cent, and these sipes break the film of water on the ice, allowing the tyre to gain more grip on the slippery surface. This additional sipe length also provides strong traction on snow-covered roads.
The Michelin Pilot Alpin is available in ‘H’, ‘V’ and ‘W’ rated sizes.