You can go down by one tyre size and one speed index letter. However, you need to check your manufacturer's manual to see if the new equipment is approved. Otherwise, you may have problems with insurance cover.
Manufacturers recommend different tyre sizes for cars and according the season. For example, if you have a Renault Clio IV 90hp, you can fit a 185 65 R15 88T in winter instead of a 195 55 R16 87H in summer.
This is interesting, because a smaller tyre will provide you with superior performance in winter weather conditions: reduced risk of aquaplaning, better grip, and a more comfortable drive.
You can build your winter pack (steel rims + winter tyres or alloy wheels + winter tyres) on our website with just a few clicks of your mouse using our configurator.