What is the Three-Peak Mountain Snowflake Symbol?

Over the past several years, we have seen a large influx of all-season and all-terrain tires that are severe snow service-rated, and therefore branded with the three-peak mountain snowflake (3PMSF) symbol. This is a trend we expect to continue, with the three-peak mountain snowflake symbol eventually becoming the norm for all-season tires. While these tires are also labeled "all-weather" tires (Learn More), what they are called is secondary to what they represent. Contrary to the "M+S" branding typically found on all-season tires, which is simply based on the tread pattern geometry and makes no guarantees of any performance capabilities, when the three-peak mountain snowflake symbol is branded on a tire, it indicates that tire has surpassed a minimum threshold in light snow acceleration traction.

So what, specifically, does the 3PMSF symbol mean?

In 1999, The U.S. Tire Manufacturers Association (USTMA) and the Rubber Association of Canada (RAC) agreed on a performance-based standard to identify passenger and light truck tires that attain a traction index equal to, or greater than 110 (for the 14" reference tire, 112 if it's the 16" reference tire) - compared to a reference tire which is rated 100 - during the specified American Society for Testing and Materials traction tests on packed snow. The standard is intended to help ensure drivers can easily identify tires that provide a higher level of snow traction, and tires meeting that standard are branded with the three-peak mountain snowflake (3PMSF) symbol.

Some important information to remember about 3PMSF branding.

• Testing measures a tire's acceleration traction on medium-packed snow only. Braking and turning on snow, along with ice traction are not components of the test.
• Tires branded with the 3PMSF symbol are expected to provide improved snow traction beyond a standard M+S branded all-season tire, however 3PMSF-branded all-season and all-terrain tires cannot match the traction of dedicated winter / snow tires in all winter weather conditions and should not be considered a replacement for where and when a dedicated winter tire is needed.

Are tires with the 3PMSF symbol the same as Winter tires?

All Winter tires have the Three-Peak Mountain Snowflake (3PMSF) symbol, but not all tires with the 3PMSF symbol are Winter tires.

Since the ASTM (American Society for Testing and Materials) test does not measure braking or lateral traction, the bar to qualify is achievable by many tires across many categories. While testing has found that tires with the 3PMSF symbol do generally outperform standard all-season products when braking and cornering in winter weather, the symbol itself is not a guarantee of that - particularly when it comes to non-winter tires.

We have several articles several articles several articles several articles several articles on Winter tires including a useful FAQ useful FAQ useful FAQ useful FAQ on the subject - but their specialized compounds, tread designs, and construction make them uniquely advantaged in handling the freezing temperatures and slippery conditions drivers face during the coldest months of the year. Similar to the way dedicated racing tires will outperform even sport-leaning touring products, dedicated Winter tires offer the same advantage. They are simply constructed for a specific purpose, and while ongoing research, development, and engineering by tire manufacturers has narrowed the gap between all-weather and Winter tires, the reality remains the same. All-weather tires should not be considered a replacement for dedicated Winter tires.