Opinion: using winter tyres on your 911
There are a whole variety of things that guarantee my full attention, but high on that list is my wife announcing that she thinks there is something wrong with the car. I try to keep my voice calm as I casually ask her which one, and I totally fail to hide my relief when I discover it is her Golf, rather than my 911, that’s giving her cause for concern.
Our Golf is a very nice, low mileage, 170bhp turbo diesel, which my wife wanted because it will more than hold its own on the autobahn when she visits relatives, while still delivering over 50 miles to each gallon of the unpleasant-smelling stuff it runs on. Consider it a thinking woman’s pocket rocket, in fact. I bought the car early last year and it had been totally reliable – up to now. Going round a roundabout one morning, it suddenly decided it was going to go straight on, though miraculously there was no damage to the car or driver. It had then apparently put itself right for the cautious journey home, prompting my first thoughts to be of black ice. However, the temperature outside was still above freezing. Perhaps a truck had spread some of its diesel on the road surface? Driving off to investigate, I got no further than the first roundabout before exactly the same thing happened again. As I slid, I had just enough time to try to guess how much a smashed near side alloy was going to cost before the car finally stopped safely, just short of the barrier.
I drove to my local independent VW specialist, who gave the steering a 30-second check before asking how fast I had been going. I admitted that I had been driving quite enthusiastically, but certainly not excessively fast, and he laughed. The problem, it seems, came down to the tyres and the turbocharger. To extract 170bhp from their plodding oil burner, VW had bolted on a whopping turbo that resulted in turbo-lag reminiscent of the first Saab Turbos – back then you planted your right foot and still had time to say a couple of Hail Mary’s before a massive hand shoved you up the road, or off it if you were unlucky. The technician guessed that when I was negotiating the roundabout I had put my foot down with a little too much enthusiasm, and when the power kicked in it simply spun the driving wheels, leaving me with no grip and a car that was determined to leave the roundabout via the shortest possible route. I asked why had I never experienced this before, and he pointed to the tyres and the thermometer on the wall reading two degrees Celsius. “That tyre gives fabulous grip when it is in its designated temperature range, and rubbish grip when it’s not. Today, it’s outside that range.” Just to rub it in, he added, “That’s why it’s called a summer tyre.” He was enjoying my discomfort a bit too much.
This reminded me of a trip in my 911 to visit my petrolhead brother-in-law in Austria early last spring. Which brand of winter tyres had I got fitted, he asked? When I told him I still had my usual Continentals on, and that we Brits didn’t really do winter tyres, he gave me that look of disbelief he normally reserves for people who tell him they don’t like apple strudel with double cream. Fitting winter tyres is the law in Austria, he told me, but even if it wasn’t, only someone who had been hitting the Schnapps far too hard and for far too long would even consider driving in winter without them. Every main dealer has a large storage facility where their regular customers store the set of wheels not in use, and each spring and autumn they take their car in to have them swapped – for a fee, of course.
It is tempting to be cynical and dismiss this as mere marketing, selling us something we could probably do without, but recent research makes this a difficult argument to accept. A sports Coupe was tested on a snowy surface similar to the roads many of us have had to face in the UK in recent winters. It was fitted in turn with Bridgestone Blizzak winter tyres, Continental all-seasons and finally Pirelli PZero summer tyres. From 30mph the winter tyres stopped in 74 feet, the all-seasons in 135 feet and the Pirellis, probably similar to the tyres on your 911 today, in 332 feet. By the time the Pirelli-shod car reached the distance at which the winter tyres had totally stopped, it had only managed to lose 4mph. In the extra 258 feet it travelled, the ABS suffered critical brake fade, with the pedal dropping to the floor. By then, the car had no grip and no brakes. And just in case anybody thinks the safest compromise might be to use winter tyres all year round, they repeated the tests in the summer and predictably got the opposite results, with the winter tyres needing far longer to stop than the summer set.
So where did this leave me and my wife’s Golf? Well, instead of the one alloy wheel I feared I was going to have to replace, I am now going to have to find four. Even if I can find a suitable set, I will have no change from £1,000 by the time they are wearing a set of winter rubber. Then, of course, there’s the trickier question of my 911. Porsche tell me it should be wearing winter boots as soon as the temperature drops below seven degrees celsius, and my OPC will sell me a package for around £4,000. Maybe those who tuck their 911s away in the garage over winter know what they are doing after all…