Do you really need winter tyres?

How does a winter tyre work?

At the heart of the winter tyre’s advantage is its use of a softer compound rubber than uses a higher silica content – a combination that allows it to retain its suppleness and grip as the temperature plummets. Summer rubber hardens below 7deg C, which means it tends to ‘skate’ over cold and damp surfaces.

Many winter tyres also claim to have deeper grooves or channels in the tread that help them clear standing water and slush more effectively. 

However, independent testing reveals there’s often very little difference in resistance to aquaplaning (where a layer of water forms between the road and tyre, causing a total loss of grip) between summer and winter rubber; rather, it’s just that the latter is better able to find grip on the cold surface when the water is finally cleared.

One area where winter tyres really excel is in the snow, and this is thanks to their ‘sipes’ – small cuts in the tread blocks. Contrary to popular belief, these types of tyres don’t cut through the snow in the fashion of off-road rubber that digs through the mud to find a grippier surface below. 

Instead, the sipes hold snow and create a surface that allows more snow to ‘stick’ to the tread, which actually increases grip. It’s similar to rolling a snowball: the snow sticks to itself.

Can I use winter tyres all year round?

Technically, yes you can use winter tyres throughout the year, but as the temperature rises through spring and summer they won’t be at their best. 

Of course, winter tyres will still be a safe option, but the softer compound and special tread patterns simply aren’t as effective at dealing with warm, dry Tarmac.

For starters, you’ll get less grip than a standard summer tyre, meaning lower cornering speeds and longer braking distances. You’d expect a softer compound tyre to actually be grippier in the dry, but as the treads and carcass heat up they become less effective, essentially sliding across the Tarmac at speeds at which a summer tyre is still clinging on gamely. 

Moreover, this extra slip also leads to greater wear, meaning you’ll be forking out for a new set of boots sooner than you’d think. Then there’s the extra rolling resistance, which leads to a drop in fuel efficiency. And for keen drivers there’s also the sloppier steering response and reduced feedback that come hand in hand with winter tyres being used in warmer conditions.

As a result, many drivers change the wheels and tyres to suit the season, storing their winter rubber until the temperatures drop. Of course, you might not have space to squirrel away a set of four wheels for months on end, but many tyre-fitting centres and car dealerships offer just such a service for a modest outlay.

Is there any legal requirement to fit winter tyres?

In the UK there is no law that dictates what sort of tyre you should use. The only legal stipulation is that there should be at least 1.6mm of tread depth across three quarters of the centre. Once the rubber wears below this figure you risk a fine of up to £2500 and licence penalty points per tyre on your licence.

However, if you’re planning a trip across the Channel over the winter months, then it’s worth bearing in mind that many countries recommend winter tyres, while a few even make their fitment mandatory. 

In Austria and Germany winter tyres are compulsory between the end of October and the end of March, while in France they are mandatory in certain regions that are susceptible to snow (such as the Alps and Pyrenees). Other European countries strongly recommend winter tyres, with many demanding drivers carry snow chains in case of emergency.