I've used the search function, but can't find an answer. Is there a date when you must put your winter tyres on? We got a car last week that came with a set (hooray) and I wondered if there was a given official date, eg. would our canton say November 26th is winter tyre day. If so, where would it be announced?
Well, I do not have documentation or test references for that...
Let me sum it up as I see it:
In winter without snow, the difference between good summer tyres and good winter tyres is relatively small and may well be smaller than between different tyres within the respective groups. I don't regard it as reckless to use (good) summer tyres in those conditions.
In ice or snow, the difference is huge and it is iffy to use summer tyres, even if you are likely to get away with it if you are somewhere flat and you take a lot of care (been there, done that).
An obvious point, but it does depend where your driving. If you're going up into the mountains you'll need them for longer and definitely notice the benefit
Thanks, I'll probably just be doing to school run, around 10km through Baar for the foreseeable future, maybe one day I'll insure the car for abroad and do some shopping in France or Germany
Ah but your insurance should already cover you abroad except in select countries (check the details on the green card the insurer is supposed to send you).
If you (like me) live in Basel where there rarely is snow/ice, AND can leave the car in the garage those days (we can), then there is no particular risk.
If that is not the case, or you want to go to the hills, do get proper tyres for it.
When I first came to the world of winter tyres after years of struggling with "just tyres" in the UK I thought too that they were for snow. I then went and asked a specialist and have since seen plenty of statistics and research. There are two differences between winter and summer tyres. With winter tyres the profile generally throws out debris better. That debris could be mud, snow, leaves it does not matter. This actually though only makes a difference if you have old tyres. New tyres summer and winter will both perform similarly on warm snow. Winter tyres are designed to work in temperatures under 7°C. As the temperature sinks the difference in performance grows dramtically. At -5°C on a dry road winter tyres will bring you to a halt in a third the distance of summer tyres like for like. Given that I do regard it to be reckless to use summer tyres when it is cold. In other words when the temperature falls below 0°C it is reckless to be on the street with summer tyres and if you get into an accident in these temperatues you will be dealt with accordingly...
The graphs do not tell the whole story though. The braking power of summer tyres reduces enormously as the temperature drops. If they had bothered to show the temperature at 0°C you would not have seen any graph where summer tyres were close to winter tyres. And of course as the temperature drops the difference increases. Go to a tyre dealer and ask him for information...
It definitely was not an ADAC test. ADAC lobbied for legislation change to make it an offence to drive in winter conditions with non-winter conform tyres - Note the mere fact you get in the car and drive is an offence!
ADAC independent tests further show that the breaking distance between summer and winter tyres on wet or snowy conditions is triple at 60km/h...
Here is what ADAC have to say: ADAC Note this is in German.
I always thought that winter tyres were a bit of a con by garages/tyre manufacturers.
Then about 15 years ago I was driving up the road to Flumserberg. It was snowing with about 8 - 10 cms lying on the unploughed road. I had a old rear-wheel drive Opel Ascona and in front of me was an identical model from Holland. The only difference was he was all over the place - fish-tailing up the hill.
Eventually they slowed as the road got steeper and finally lost all grip and were stuck with rear wheels spinning. As they jumped out to inconveniently put on their chains on in the middle of the road, I was able to restart on the hill and, to their astonishment, gently drive past without any wheel spin. It may perhaps give only 10% more grip - I don't know, but that was all that was needed...
People always say "Boohoo it's a conspiracy to make us buy more tyres".
Yet they don't seem to realise that having two different sets means you get to use each set +/- twice as long since you only use them for 6 months of the year instead of twelve... with the added bonus of being safer.
Even when living in a flat area you could be faced with a downhill ramp to a garage entrance which can be rather tricky when as little as 1 cm of snow and summer tyres are combined. If you're in luck, you'll be sliding down the ramp towards a barrier fixed with plastic bolts. If not, it will be towards a solid metal garage door...
As mentioned before, snow tyres where a bit of a mystery to me back in Australia. But, being a skiing fanatic did get to drive in the snow on occassion. But with fat (245) summer tyres, a light rear end (rear wheel drive) and a super overpowered engine it only took a couple of cm of snow before I was in the cold putting chains on with frozen fingers.
Over here I have discovered winter tyres. With only slightly narrower tires I was able to get my car out of a car park with 20cm of fresh.
But I don't think anybody is disputing the advantage winter tyres in the snow and ice. The big debate is on dry roads in winter, and to a certain extent wet with no snow or ice.
As this is in Danish, I will give you a translation of the interesting bit:
"Press release (26 Nov 2003) from Færdselsstyrelsen (DK Dep of Transportation, FDM (Danish Motoring Ass.) and Statens Bilinspection (the ones doing MFK)
...
We cannot give one general advice for or against winter tyres, as winter tyres are best on days with snow and ice, summer tyres are best on dry and wet road. In this connection it is important to know that information of summer tyres losing the grip at temperatures under 7degC are no longer valid. Even at low temperatures summer tyres are normally better than winter tyres when the road is dry or wet. The best and safest choise of tyres depend very much on the car type, the amount and type of driving, and if you can and are willing to leave the car the few days where it is really snowing.
..."
In Denmark, winter temperatures are normally between -10 and +5.
Do you have a link to somewhere describing the 1/3 braking distance at -5? I am happy to be convinced by facts, and there could be more recent information
Also, do you actually know of cases where drivers have been found guilty in accidents (in CH) due to summer tyres on cold dry roads?
The grip of the tyres reduces dramatically at temperatues below zero. This is then irrespective of the road conditions. It is a simple thing to test. You get a squash ball and a piece of hard plastic. Hold both in the hand and then rub both across a polished surface. Which one grips better?
As the temperature reduces the summer tyres being made of a different compound rubber become harder faster. Hence they are the hard plastic and the winter tyre is the squash ball...
You can read any manufacturers web site about the effect of cold on the tyre...