The car slews violently as the tyres scrabble for traction on hard-packed snow. On the inside of the bend, the headlights reflect a wall of solid ice, the glare as white as my knuckles…
A few battered marker posts are all that lies between us and a 200-metre drop. Oh, and did I mention that it’s midnight and my driver is a 65-year-old German with no fear? But, despite our high speeds, this is no rally car – it’s a Skoda Octavia. And my driver, fearless Felix, will tackle this same mountain pass three times for every winter tyre we test.
Testing winter tyres in the Alps
Every January we travel to the Swiss Alps to assess the latest tyres on snow and ice. We work at night when the temperature is more constant (usually -15°C).
In addition to timed runs up the mountain pass, we test braking ability on snow by slowing from 19mph to 3mph. And we calculate traction by measuring the degree of wheel-slip as speeds increase. On ice, we brake from 16mph to 3mph and measure how far the car travels. Felix and his team then complete laps of a circular ice track as fast as they can.
Dry and wet road testing takes place at a test track. On dry land, we measure braking distance from 62mph to zero, then assess stability on a high-speed handling course, with sudden lane changes thrown in to upset the car’s balance. On wet road, we test braking from 50mph to 12mph in continuous-rain conditions, plus there’s another tricky handling course to complete. The tyres’ ability to disperse water is assessed as well, both in a straight line and when cornering on a circular track.
Our noise rating is based on subjective assessments from inside the car and trackside measurements while coasting with the engine off at 50mph. Fuel economy is calculated at 62mph over 1.25-miles. We measure the wear on each tyre after 3,100 miles, then extrapolate the results to predict which will last the longest.
So, that’s how we test winter tyres. Did you go and buy a set this year? Last year in our poll of 1,653, just 31% said they’d be fitting winter tyres. The majority (42%) said they would be keeping their summer tyres, 15% using all-season tyres, and 6% snow socks. What about you?