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9 Nov 2013

Winter Tyres - A view from Sweden

Budda, a test driver for Volvo, Head of Pimpstarlife Car Division and resident of Sweden (where it snows quite a lot) responds to our recent article: "Winter Tyres - Fact or Fiction?"

I've worked with driving cars in one way or the other since the beginning of 1998 and have been doing between 150-200,000 kilometres a year since then.  Almost half of that mileage has (unfortunately) been done in cold, mostly wet or often snowy and icy conditions.

For us here in Sweden it is, as in Germany, a legal requirement with winter tyres from 1st December until the last of March.  


There is an ongoing debate here in Sweden about which is the better choice. Studded or not.  Low emission vehicles can park (almost) for free in the city. This is, however, provided you use winter tyres without studs. 


In other words: people with low emission vehicles are more or less forced to use tyres without studs.
I drive about 150 kilometres round trip to work each day. Half is highway, half is often snowy and icy roads. 

The reason given for this regulation is that studded tyres rip up particles from the road (tarmac) which are allegedly dangerous to inhale.  There is, however, one thing they didn't think about. Studded tyres also tear up the surface in the ice. 

What happens now, with more and more people using friction tyres, is that the ice gets polished. This makes for extremely low friction where cars stop and start.

One would think studded tyres are better on ice. I would say this is not a given. 


A good winter friction tyre might be better than a poor studded tyre. The compound and pattern is developing fast providing very good grip on ice even without studs.  The best ones with studs are of course the preferred choice if you know you're gonna be driving on a lot of ice. (All season tyres is a perfect mix that is poor on all surfaces, wet or dry) 


As for thread movement and vibrations I have never experienced a problem with it, as long as one chooses a good quality winter tyre.  Tyres are marked (at least here in Sweden) with a letter that says which speed they are approved for. T is for instance 190km/h. (They do in the UK too.  See Michelin guide here - Matt)
 
I've been doing stints on winter tyres in high speed without vibrations or trouble.  I can't see how winter tyres would wear out ball joints, bearings or bushes any more than a summer tyre would.  It is of course, as always, important to balance the tyres, but that goes for summer tyres as well. 

In the case of steel wheels with hub caps there might sometimes be a slight unbalance in the tyre when snow and dirt packs on the inside, but it is in the same way that for instance mud can get stuck inside a high speed summer tyre on an alloy rim providing unbalance. Wash it off.

Regarding cost, it is, over here, not that big of an issue. When you buy a new car, it will be an additional investment of course, but after that, the car will, throughout it's life, have "two pairs of shoes" provided it's driven all year round.  One pair for summer, one pair for winter. If you drive the same mileage, the sum of money will be the same or even lower. 

Winter tyres are often a bit cheaper than summer tyres, and you will probably wear out let's say two pairs of each instead of four sets of summer tyres over a given amount of time.  When you buy a used car it will most often be delivered with one set each since it's a legal requirement. 

The feeling of driving on tyres made of bubble gum.  Well, it is of course a noticeable difference changing from low profile high speed tyres to thinner, higher tyres made of a softer compound.
There might because of this be a bit of a bubble gum feeling for the first 20-30 kilometres, but once the fingertips are used to the lower friction between tyre and road (power steering will in most, if not all cases be tuned for summer tyres) and you've gotten used to different dimension and compound, the rest of the season is not a problem. 

It is of course a different experience driving fast on winter tyres and driving should be done accordingly, but it would never cross my mind to go through winter on summer tyres. 

I've been driving on winter tyres without studs from below -20°C up to over +15°C. At the hot end, the tyre will of course be a bit soft, but not in a way that compromises safety if driven with common sense. 

Conclusion: summer tyres in the winter is as bad, or rather much worse, than winter tyres in the summer. 

The ABS-locking experience sound horrendous and must have been a case of either really bad winter tyres or all weather tyres.  Going through winter on summer tyres here wouldn't even cross my mind. I wouldn't even get to work tomorrow.


/ Budda