 |
|
|
| Roger Sanders, General Manager Technical Services
at Continental Tyre Group, explains why winter tyres are ideal
for the UK's cold, damp and wet winters |
 |
| "Cold weather tyres offer
clear safety advantages on cold, damp or wet roads, too" |
Many drivers were left stranded when last year’s icy conditions
hit. Yet many might well have made it home if they had adjusted their
driving to the slippery conditions, and had their car fitted with
appropriate winter tyres. In Scandinavian countries, for example,
motorists fit their winter tyres long before the first flakes of snow
start to fall. Ask a British driver as to the benefits of winter tyres
and the answer is likely to relate to snow or icy road conditions.
What is not well known is that winter tyres, or perhaps more aptly-named
cold weather tyres, offer clear safety advantages on cold, damp or
wet roads, too. This is because specialist cold weather tyres are
much more effective at clearing water, ice and snow from the treads,
giving better grip, largely down to the rubber compounds used that
are designed to stay more flexible at lower temperatures. The chart
below shows that average monthly temperatures in the UK are below
7°C between October and April. The chart also shows how vehicle
accident insurance claims dramatically increase with the onset of
cold weather.
Note particularly the increase in October and November, not when snow
or ice is the norm, but when cold and wet/damp conditions are encountered.
When ambient temperatures fall below 7ºC, the molecules in tread
rubber progressively harden and freeze. This means the tyre is less
able to adapt to the contour of the road surface, which in turn reduces
grip levels. With cold weather (winter) tyres, the rubber compounds
are designed to remain pliant at low temperatures allowing the tyre
to key into the road surface, resulting in higher grip levels.
|
| "Advances in tread pattern
design means that modern
day winter
tyres provide high levels of road safety" |
Together with highly developed multi stripe tread patterns the combination
is such that no summer tyre can match. Modern rubber compound technology
and advances in tread pattern design mean that modern day winter tyres
provide high levels of road safety, not only in snow and icy conditions,
but also on cold and damp road surfaces, which are commonplace at
temperatures below 7°C. Shown below are comparisons of braking
distances between summer (warm weather) tyres and cold weather (winter)
tyres. At 20°C, summer tyres help a car stop quicker than winter
tyres as they are biased towards warmer climates. At 5°C, however,
the reverse is true, where cold weather (winter) tyres will bring
the car to rest in up to five metres (16ft) shorter distance.
Perhaps more importantly is that cold weather tyres perform similarly
at 20°C and at 5°C, whereas with summer tyres the difference
is very marked. In snow and on ice, winter tyres excel, which comes
as no surprise, note the amazing difference in stopping distances
on icy roads when braking from only 20mph. For all the above reasons,
Continental Tyre Group recommends serious consideration is given to
fitting cold weather tyres between October and April.
Can winter tyres be used all year round?
Whilst the short answer is yes, winter tyres can increase the fuel
consumption of the vehicle slightly. Also, both tyres are designed
for optimum performance in the two climates – so, similarly
to driving on summer tyres in colder months, drivers will find the
performance of winter tyres in the warmer months is not as good as
that of summer tyres.
|
| |
|
