Seven degrees. That's when your car tyres stop working properly. Not just when it's snowing, but when it's cold. The modern car tyre is a marvel of engineering, but it can only do so much. Seven degrees is its tipping point, the temperature at which the tyre hardens and grips less. Winter - or cold weather - tyres counter this with more natural rubber content, staying supple and finding grip where a regular tyre would struggle. When the area of each tyre's contact with the road is about the size of the palm of your hand that's important.

A cold weather tyre will stop, turn and grip better in sub 7-degree temperatures too, while the additional 'sipes' - up to 10 times more than on a standard tyre - allow cold weather tyres to perform far better in snow and ice conditions. A recent experiment showed that stopping on snow with a regular tyre from 30mph required 63 metres, while a winter tyre managed that in just 31 metres. Forget mobility for a moment; that's a safety issue.

Don't imagine that four-wheel drive is a get-out either. An off-roader or all-wheel drive car will get further than a two-wheel drive car in snowy conditions, but if there's no grip there's no grip - regardless of how many wheels are driven. That's something I've experienced first hand when a Mitsubishi Shogun I was driving to the ski slopes gave up in just a few inches of snow. No number of clever locking differentials - or chunky tyres - were a match for the tiny Peugeot 106 on the correct tyres that sailed past effortlessly as I struggled with snow chains.

That was in mainland Europe, where consumers are better informed as to the benefits of winter tyres, with many countries requiring their fitment by law. There's no legal requirement in the UK, but you just need to look at our weather statistics - and the chaos caused every year by snowfall - to see that cold weather tyres make sense. They're as quiet, no less efficient and don't need to be expensive either; particularly as, all the time they're fitted, you're extending the life of your summer tyres. They do need fitting to all wheels though - not just the driven ones - but they'll perform decently above 7 degrees, too.

It's about picking tyres for the conditions, and having a set of cold weather ones fitted makes a great deal of sense for not just mobility, but safety.

Kyle Fortune - 14 Nov 2011