What are the most important differences between summer and winter tyres?
Two points have to be especially highlighted when talking about the differences between these two types of tyres: the tyre profile and the tread compound.
Modern winter tyres feature a thermoelastic tread compound that preserves its grip even at low temperatures and therefore offers a better handling on the street than summer tyres.
- The contact patch stays elastic even at very low temperatures. It optimally adapts to the surface structure of the street.
- Various silicic acids (or Silica) are being used for the production of winter tyres. They help improving the grip on the street by a lot.
The profile of winter tyres is characterised by the high number of grooves in the tread bars. Grooves are waved sipes in the profile that grip into ice and snow and therefore form longitudinal and transverse edges. Like that, the grooves act like a milling cutter that penetrates the snow and interlocks with the driving surface. The advantages of this specific tyre profile are improved brake ability and traction. To avoid reducing the effect of winter tyres, the tread depth should never go below 4 millimeters. Should this be the case, we recommend a tyre change.
Quelle: ACE Auto Club Europa
A test by ACE Auto Club Europa demonstrates this. It states that winter tyres with a profile of 8 millimeters manage braking from 50-0 km/h in 26,2 meters, while worn out winter tyres with a profile of only 2 millimeters need 37,6 meters. On wet roadways, the same comparison has been conducted with a deceleration of 100-0 km/h. The new winter tyres needed a braking distance of 62,4 meters compared to 76,3 meters with worn out tyres.
From when should winter tyres be used?
This depends a bit on the summer and winter tyres in use. A good guideline is the fall of temperature below seven degrees. From this point, you should show enhanced alertness. Especially during morning traffic, ground frost can develop. With the limited grip of summer tyres, this poses a safety risk.
It is important to change to winter tyres before the first snow. Good to know: It is not mandatory by law to use winter tyres in every country. Read up well in advance of your business or leisure trip whether your rental car has to have winter tyres mounted or not:
- Germany and Austria: Attention, in these countries, a situational winter tyre obligation is effective. If the streets are covered with clear ice, packed snow or snow slush, or if there are icy conditions, it is mandatory to fit winter tyres in these countries.
- Switzerland: There is no obligation to mount winter tyres. You should still keep in mind that the driver should be in total control of his vehicle at all times. If he is involved in an accident in wintery conditions with summer tyres mounted, a reduction of insurance proceeds is impending.
How exactly do winter tyres effect the braking distance on snow-packed roads?
The effect of winter tyres is subject to broad research. The consensus of these studies is that winter tyres always reduce the braking distance on snow. Depending on the study design, it is apparent that they massively reduce the braking distance compared to summer tyres.
For example, the Touring Club Switzerland states that the braking distance from 40-0 km/h on snow is 50% longer when using summer tyres instead of winter tyres.
Changing to winter tyres provides a lot of benefits concerning safety and driving experience on snow-covered and wet streets at low temperatures. All-season tyres are a bad compromise that can’t stand up to changing between summer and winter tyres, not in the performance nor in financial aspects.
When should you pass on winter tyres?
It doesn’t make sense to use winter tyres all year long. At dry weather conditions and temperatures above about 15 degrees, the braking distance is longer than with summer tyres. Additionally, the tyre wear is a lot higher. The most common rule of thumb is “From O to E”, winter tyres should be mounted approximately from October to Easter.
Can the rental cars of Edel & Stark be driven without problems in winter?
All vehicles offered for rent in winter by Edel & Stark have winter tyres mounted and will get you to your destination safely and elegantly, even through adverse weather conditions. Additionally, the rental cars can be equipped with snow chains and ski racks on demand. Therefore, these vehicles are ideally suited for a safe driving experience on wet or snow-covered roads.