Due to the mild winters that the UK experiences, it is not a legal requirement to switch to winter tyres throughout the colder months. It is however recommended as general guidance that when the temperature drops below 7°c winter tyres are better suited to providing optimum performance in colder temperatures. The compound in winter tyres is able to remain more elastic at lower temperatures helping the tyre to gain stronger traction and grip which ultimately helps with handling and braking during cold snaps, ice and snow.
Aside from the clear difference in the season in which the tyres are designed to used, summer and winter tyres also contain different technologies:
The below diagram illustrates the difference in braking distances across a range of temperatures and seasons comparing winter and summer tyres:
It is not recommended to mix summer and winter tyres – the different tread designs and compounds produce different handling characteristics which could make the car unstable.
If you plan to switch to winter tyres throughout the colder months of the year, you should store your tyres correctly: