Snow-tyre danger

Used snow tyres are found on some Japanese-import used cars, and are also imported and sold by used-tyre dealers.

Snow tyres are easily identified: they have a characteristic block pattern (pictured right). Recent snow tyres often have a snow symbol on the sidewall (pictured below right). If you're in any doubt, ask a tyre dealer to check.

• Snow tyres should only be used where they are needed - in alpine areas during winter.
• They should always be used in sets of four, and replaced before they get old and worn.
• Never mix snow tyres with normal tyres, even in matched pairs on one axle. If the spare is a snow tyre, only use it at low speeds. Better still, have a normal tyre fitted.
  

4WD vehicles often have M&S (mud and snow) tyres fitted. These are suitable for all-season road use, as well as for mud and snow. But it's still best practice to fit M&S tyres in matched sets of four. Note that snow tyres for cars are often rated M&S.

Changes to snow-tyre rules

Since April 2010 if you need snow tyres, they must be fitted to all wheels of the vehicle. They also must have a minimum tread depth of 4mm – more than twice the 1.5 mm depth for normal tyres.

This change was brought about by the deaths of four people in accidents involving cars with snow tyres fitted only to the rear wheels. Tests later showed this combination was highly unstable in certain conditions. We called in 2008 for the rule to be changed and fortunately there have been have been no further deaths as far as we know.

We think snow or winter tyres should only be used in the conditions they’re designed for: on snow and ice in winter.