Auto EXPRESS magazine has published two videos
showing the shorter stopping distance of winter tyres and how they allow a front
wheel drive car to climb a snowy slope better than a 4WD on all-year round
tyres(!)
If a 4 wheel drive car is fitted with "Sport" tyres,
optimised for grip in summer, the tyre's poor snow grip may undermine the
advantage of 4 wheel drive.
Hill Climbing.
Stopping Distance
From 30mph winter tyres will stop you 8 metres shorter
(two car lengths) on snow.
Tread pattern has a big effect on grip in snow. You
might expect snow tyres to need big chunky tread patterns, but they also use
fine side-to-side slits in the tread that help them stick to the snow crystals
(rather like when you roll a huge snowball). These give a big improvement in
both traction and stopping distances on wet roads as well as ice and snow.
Below 7 deg. C. the rubber of normal tyres becomes
stiff and less able to mould itself around the stones in the road surface,
reducing the grip available.
Winter tyres use a rubber that remains supple below
7deg C.
The UK has average temperatures below 7 deg C for 4
months a year, so winter tyres are valuable even without snow.
Their use in winter is compulsory in some northern
European countries. They don't limit your speed, and some people use them all
year round.
If you want to give these tyres a try without great expense, some part worn tyres can be bought very cheaply.