Under the skin: tires that adapt their tread to the conditions Car News

Since the appearance of winter tyres, followed by all-season tires like Michelin’s Cross-Climate or Pirelli’s Cinturato All Season, tire design has become even more technical than it used to be.

The latest from Pirelli is the Scorpion, a dedicated SUV tire that includes summer, all seasons and full winters in the range.

Advanced compounds play a big role in the development and advancement of tire technology and the concoctions used in the Scorpion range are a good example of this. A new generation of synthetic rubber compound is said to give the summer tire a kind of “mechanical intelligence” thanks to the elastic characteristics of specially developed polymers as well as silica and resins to increase grip.

The properties of polymer-like materials (polymers) change with temperature to adapt to surface conditions. Pirelli says the compound for the new tire has been developed using a patented process derived from its motorsport experience to produce a compound that is more uniform in consistency, improving performance over a longer period of time.

The Scorpion SF2 all-season tire has sipes (the tiny slits in the tread) that change shape to adapt to cold, harsh winter conditions and wet or dry tarmac. The sipes are open to get better buy-in on snow, but in wet or dry conditions they close to increase the stiffness of the individual blocks, which is important for grip and steering feel, especially when you’re work hard in the dry.

This is because the tread changes from a winter pattern to a summer pattern depending on the conditions.

The blocks themselves, although derived from the most recent Cinturato All Season SF2 design, have been beefed up and engineered to reduce road noise on heavy SUVs. The compound adapts to the conditions just as it does in a summer tire too – soft and supple in cold, wet weather and becomes stiff to give tread stability in dry, grippy conditions. Pirelli says this was achieved by bonding silica particles with the polymer materials.

Scorpion Winter 2 tires take a new approach to sipes, which improve grip on low temperature surfaces as well as snow and ice. The 3D sipes are “stretchable” and can change from a linear shape to a zigzag pattern to increase their surface area as the tread wears.

Pirelli expects 400 tire size variations across the range to join manufacturers’ original equipment lists. Half of them are intended for new electric vehicles and 75% of the tires listed so far in the summer range alone are intended for electric vehicles. The latest version is also said to push the game forward when it comes to reducing road noise and power consumption, while improving braking performance at the same time.