What are winter tyres?
Most UK cars are fitted with summer tyres, and some with all-season tyres. But winter tyres are designed specifically to remain supple in colder temperatures and maximise traction when driving on snow and ice.
The key differences are:
they use a softer rubber compound (usually by including more natural rubber in the mix),
the surface of the tread blocks is covered with little jagged slits – called sipes,
they generally have deeper tread grooves than conventional summer tyres.
How much do they cost?
As with regular tyres, winter rubber sells at a wide range of prices, with budget models in a common size suitable for a family hatchback available from less than £70 per wheel. A comparable winter tyre from a premium manufacturer can cost around £150 but, as with their summer counterparts, they are likely to offer greater levels of grip and braking performance.
What are winter tyres good at?
They are good at gripping in cold, damp conditions below 7C, and offer improved traction on slippery surfaces. The key to their improved grip on wet and ice-covered surfaces is the sipes, which provide hundreds of small extra ‘edges’ to grip the road as the tyre rotates. The sipes help not only because of their edges but because they enable localised movement of the rubber as the soft compound clings to the road. A larger single solid-tread block, like the ones you see on summer tyres, would stay rigid in such conditions and be unable to maintain grip as effectively. Winter tyres are also designed to gather a snowy 'in-fill' in the tread grooves and in the sipes to help with grip on packed snow. Nothing grips snow better than snow itself and winter tyres exploit this by gathering and holding as much of it as possible. The extra-deep tread grooves also help the tyres to disperse surface water and usually increase resistance to aquaplaning, where the tyre passes on top of the water rather than through it, increasing the risk of losing control of the car.
What are winter tyres bad at?
At temperatures above 7C they offer significantly poorer performance in dry conditions than summer tyres. This can mean a marked increase in braking distances and poorer grip on bends. Winter tyres also suffer from increased wear rates if used in warmer temperatures.
Are they just for snow and ice?
No. They are designed for use in all winter conditions – tyre manufacturers claim this means any weather below 7C. Ideally, you need a second set of rims on which to fit your winter tyres. In many countries where winter tyre use is mandatory drivers often opt for steel rims, which are less likely to corrode after exposure to winter grit. They are also less expensive to repair or replace if you accidentally slide into a kerb. If you’re fitting winter tyres, it’s worth carrying a winter spare as well since fitting a summer spare alongside three winter ones could make your car’s handling more unpredictable due to different levels of grip at each corner.
Do I need winter tyres in the UK?
Winter tyres aren’t mandatory in this country, although they are in other parts of Europe that experience extreme weather for prolonged periods each winter. However, they can be a prudent investment, particularly if you live in remote areas at risk of being cut off in bad weather without a functioning vehicle. However, for drivers who use well-serviced urban roads, it can be harder to justify the hassle and expense of switching to winter tyres during a cold snap, despite their improved performance.
When should I fit winter tyres?
They need to be fitted before bad weather strikes. Waiting until the roads are frozen and the car is under a snow drift will mean you’re unlikely to be able to fit them. In the European countries where the use of winter tyres is mandatory, most people have them fitted around October and then replaced with summer tyres around March, when the worst of the cold weather has passed.
What alternatives are there to winter tyres if it turns cold?
All-season tyres are a halfway house between winter and summer tyres. They can be left on the car all year round, but generally don’t perform as well as the best summer tyres in warm weather or as well as good winter tyres in cold conditions. There is also a newly emerging class of tyre, first seen with Michelin's Cross-Climate model, that is essentially a summer tyre, but with the requisite tread pattern and supple rubber compound for winter-tyre classification. This means they can legally be used year-round in countries that enforce winter tyre use, whereas all-season tyres cannot. Tyre socks are a quick fix to get you off a slippery snowy drive or ungritted side road. These fabric ‘socks’ wrap round the tyre and give extra grip on the snow and ice. They cost around £50 for a pair.
Will winter tyres affect my insurance?
Initially, as winter tyres were something of an unknown quantity, there were a number of instances of them being treated as a modification in the eyes of insurance companies, resulting in increased premiums. However, most insurers now recognise them as a worthwhile safety improvement and don’t penalise drivers for using them, but it’s worth double checking with your insurer.
If I don’t fit winter tyres, what are my options in snowy conditions?
Check your existing tyres are in good condition - preferably with at least 3mm of tread left across 75% of the tyre width, but certainly with more than the 1.6mm legal minimum. Look for any signs of damage to the tread or sidewalls as this could cause sudden tyre failure, which will be even harder to control in poor conditions.