Asymmetric tread

A comparatively recent invention: the idea is that the tread pattern is split lengthways into two parts. One, usually the outer one, has a classic look and is meant to provide good grip on tarmac. The other part, usually the inner one, is meant to provide the off-road function, meaning grip on snow and slush. It is hard to say anything definite about how effective a design like this is. What you probably need to understand here is that both functions are delivered, but the useful area of each part is halved, so the effectiveness of each function drops too.

The most accurate statement is probably that an asymmetric winter tyre is a good alternative to a classic winter tyre, possibly even with improved figures, although a lot here depends on the specific model and maker. The one thing that can be said for certain is that tyres with an asymmetric tread are definitely more expensive than the classic kind. Whether it is worth paying for that kind of versatility is for you to decide.