There's an age-old theory that proposes one should go for narrower tyres in the winter because a narrower tyre puts more pressure on a smaller contact patch, thus generating more grip. The contrasting argument is that you should use a wider tyre, as more surface area on the road will generate more grip. But as Jonathan Benson at Tyre Reviews discovered, it doesn't really matter whether you go wider or narrower for your winter setup.
Benson wanted to test the theory of wider versus narrower winter tyres himself, so he sourced four sets of Hankook tyres to run on a BMW 3 Series around a snow-covered closed course, each wider than the next. The tyres ranged from 205 section-width up to 275s, with the 205s installed on 16-inch wheels, the 225s resting on 18s, and the 255s and 275s mounted on 19-inch rims.
While there were subjective differences in feel and feedback between the sizes, the numbers don't lie. The narrowest tyre performed the best in acceleration testing, but did the worst when it came to braking. And for lap times, the middle 225 section-width tyre performed the best. But all of the results are so close that you probably wouldn't notice the difference.
More Winter Tyre Tests
The main conclusion, Tyre Reviews says, is that you'd find more of a variance in objective performance between a good winter tyre and a bad winter tyre using the same tyre size. So if you're shopping for winter rubber, your best bet is to focus on brands with good reviews rather than stress about what size you should choose.
Source: Tire Reviews / YouTube