With a weekend of winter weather forecast, the Institute of Advanced Motorists has issued advice on the pros and cons of using winter tyres.
There are two main differences between winter and normal tyres, says the IAM: the tread pattern and the materials used. Winter tyres have a tread pattern of wider grooves and narrow slits at the edges of the tread area, all of which help to give better grip on snow and ice.
In terms of materials, winter tyres use a type of rubber which stays soft and grippy even when the temperature drops well below zero. The rubber used on the tread of a standard tyre becomes stiffer as the temperature drops, causing grip to reduce below seven degrees C.
According to the IAM, the primary drawbacks of winter tyres are storage and cost. A set of steel wheels and tyres can cost upwards of £500, and while switching to winter tyres permanently is an option, the IAM advises against it, stating that they offer less grip once the weather warms up, will wear out more quickly and cause the car to use more fuel.
The advice for motorists who do not want the inconvenience of storing extra wheels and tyres is to consider fitting all-season tyres. These use the same rubber compound as winter tyres and should be marked on the sidewall with a snowflake or mountain symbol, or marked "M+S" (Mud and Snow). However, they are a compromise and their ultimate performance is not as good as a standard tyre in the summer or a winter tyre in snow and ice.
For those who want to keep their standard tyres an alternative option is to use them in conjunction with snow chains or snow socks. The former cost from £50 for an economy set and are effective in deep snow. The drawbacks are that they can be difficult to fit and because they increase the width of the tyre they might also affect suspension or ABS brake operation. Driving on a clear road surface with snow chains could also cause damage, meaning they must only be used on snow.
Snow socks, while ultimately less effective in deep snow, will provide sufficient grip for most UK conditions, are easier to fit and can be driven on clear roads (although they will wear out quickly). Typically they cost from £40 a set.
IAM chief examiner Peter Rodger said: "With extremes of cold weather being unusual here, and the UK government showing no signs of making winter tyres compulsory, there is no obligation to invest in them. Nevertheless, a set of winter tyres could be a sensible option for some UK motorists, for example those who live at high altitude or in remote areas. For the rest of us, whether the cost is justified depends on individual circumstances such as annual mileage and whether you have the option to avoid driving in extreme conditions."
