What size for winter tyres? TCS says narrow tyres are more efficient

One tyre, but 5 sizes tested

What is the best size for winter? This is the question Touring Club Suisse, the largest motor club in Switzerland, has asked in a new tyre test. This review differs slightly from standard tests in that not several, but only one tyre model was tested in 5 different sizes:

• 195/65 R15 91H
• 205/55 R16 91H
• 205/50 R17 93H
• 225/45 R17 91H
• 225/40 R18 92V

The Dunlop Winter Sport 5 was selected to equip the Volkswagen Golf 7 test car. Why this model? Because, its tread pattern and rubber compound are the same for all sizes. TCS conducted the tests in dry, wet, snow and icy conditions.

Narrow tyres are better in winter

On snow covered roads, it is better to drive with the narrowest tyres. Although all the tyres tested had identical braking distances, the difference was felt in acceleration and handling tests. The Touring Club Suisse noted a significant improvement in snow traction with the narrowest tyre (size 195/65 R15) compared with wider tyressuch as the size 225/40 R18. In addition to their less efficient performance on this surface, 18-inch tyres can very rarely be fitted with snow chains, which could improve their performance. This is why TCS does not recommend this tyre size to drive on snow covered roads.

Yet, in dry conditions, which is not the main reason to use a winter tyre, tyres in the size 225/40 R18 are the most at ease. If the difference is less obvious on snow and braking distances remain the same for all, the Touring Club Suisse has found a difference in terms of stability and handling. With its stiffer sidewalls and wider contact area, the Winter Sport 5 in the 18 inch size has, in particular, the upper hand over tyres in the 195/65 R15 and 205/50 R17 sizes.

But in wet conditions, once again, it is the narrower tyres that stand out. The difference may be less than on snow, but compared with the smaller sizes, 225/45 R17 and 225/40 R18 sizes are less efficient for aquaplaning resistance and wet handling. If tyres in the size 205/55 R16 and 205/50 R17 are roughly equivalent, TCS nevertheless noted slightly improved performances with the 195/65 R15 tyre.

On ice, all tyres are equivalent despite a very slight improvement in lateral stability for larger tyres in the 225/45 R17 and 225/40 R18 sizes.

For wear, the tyre with the smallest size (195/65 R15) is slightly less resistant than the other models. For consumption, the largest tyre (225/40 R18) is slightly less efficient,which is confirmed on the tyre label. It is rated E for rolling resistance whereas the other models are rated C.

What price for each size?

With rezulteo you can easily compare tyres and find the best price for the Dunlop Winter Sport 5 in the 5 sizes tested by the Touring Club Suisse. The tyre is cheapest in its smallest size, 195/65 R15 91H. Prices start from £57.00 whereas for the largest size, 225/40 R18 92V, the starting price is £96.30.*

With our tyre comparison tool, you can see that the smallest winter tyres are the most advantageous, both economically and in terms of expected performances.

*Price recorded on the rezulteo, 21st January 2019.

• Dunlop
• Winter tyres