Summer tire with winter approval: Shaking the foundation of traditional tire classification

Traditionally, tires were divided into two distinct types: summer and winter. Today's all-season tires were once categorized as multi-season or universal, designated with the M+S symbol. The main differences between summer and winter tires lie in the unique tread pattern and rubber material used. Winter tires incorporative features that enhance flexibility in cold conditions, while their characteristic sipes (wavy cuts on tread blocks) ensure optimal traction in snow-driven roads.

The introduction of all-season tires brought a subtle paradigm shift in the tire market. Essentially, they were winter tires adjusted for use at higher temperatures throughout the year. Put another way, they are a slightly inferior version of winter tires, formulated with a hardened compound to resist premature wear during summer.

In designing all-season tires, manufacturers sought to find the perfect balance of rubber mix and tread pattern to ensure satisfactory performance during both summer and winter. A significant turning point was in 2016 when Michelin debuted the world's first summer tire with winter approval (Cross Climate). This tire was a response to fluctuating global temperatures where even winter conditions in many European countries were not as harsh. However, this tire created some confusion in the naming convention.Though not termed an all-season or winter tire, it bore a striking resemblance to summer tires in its tread pattern but had winter approval. Allow me to elucidate further.

This fact might come as a surprise, but let me elaborate. Our discussion here is mainly about passenger car tires.

Tires can either have road approval or not. If they do, they are permissible for use on public roads. Not all types of tires gain this approval. For instance, sports tires like slicks or spiked rally tires, or gravel tires. However, surprisingly, products with very similar features might gain road approval.

If a tire has road approval, it is a road tire. Despite various names and symbols on the side, it is still essentially a tire. The manufacturer can label it a winter, summer, spring, autumn, or all-season tire, with one minor exception.

The exception lies in the so-called alpine symbol, also known as the 3PMSF sign (Three-Peak Mountain Snow Flake). This sign, specified under UN ECE Regulation 117 and later adopted into European law in 2009, denotes a tire's winter-readiness. This was in response to the need for legal directives pertaining to the use of winter tires in certain countries during specific periods or on special road segments. However, these legal requirements could only be laid down if the requisite type of tire was legally endorsed. To be blunt - it isn't feasible to enforce the use of winter tires without a clear definition of what constitutes a winter tire, which can't be left up to manufacturer labeling. The 3PMSF sign, on the other hand, conveys that a particular tire model has been winter-tested and meets the winter approval standards. In simple terms - it has both road and winter approvals.

Consequently, any tire, regardless of how the manufacturer brands it (e.g., summer, winter, all-season), is a winter tire if it bears an alpine sign on the side. Therefore, the market has road tires and road tires with winter approval, i.e., winter tires. Officially, there are no summer, all-season, multi-season, or universal tires. Only two categories exist: winter and all other tires.