What Does the Three Peak Mountain Snowflake Symbol Mean?
Understanding snow ratings on tires
As you hit the roads this holiday season and get your car "winter driving ready", you may be checking out different tires and wondering what the difference is in snow ratings. Let's begin by discussing the Three Peak Mountain Snowflake (3PMSF) symbol.
When you see a 3PMSF symbol on a tire, this is a certification mark indicating that a tire meets specific performance criteria for use in severe snow conditions. It is also known as the Alpine Symbol and is commonly found on the sidewalls of winter and all-weather tires. When a tire displays this symbol, it signifies that it has passed standardized testing for traction and performance in snow conditions, as defined by the the US Tire Manufacturers Association (USTMA) and Transport Canada.
To earn the 3PMSF symbol, the tire must demonstrate at least a 10% improvement in snow traction compared to a standard tire. The testing typically involves traction measurements in packed snow conditions, indicating that the tire is suitable for extreme winter conditions and provides better grip and safety on snow, slush, and ice.
In some regions with severe winter weather (e.g. parts of Canada, Europe, and some US states), tires with this symbol are often required by law during winter months. The symbol works to differentiate winter-rated tires from all-season tires, which do not necessarily meet the same performance standards.
What’s the difference between a Three Peak Mountain Snowflake (3PMSF) symbol and an M+S rating?
A Three Peak Mountain Snowflake (3PMSF) symbol and the M+S (Mud and Snow) marking are both indicators of superior tire capabilities in the snow, but they differ significantly in terms of testing, performance, and purpose. Here’s how they compare:
Three Peak Mountain Snowflake (3PMSF) Symbol indicates a higher performance standard and is intended to show that the tire has met specific, rigorous testing requirements for severe snow performance, ensuring that the tire is suitable for extreme winter conditions, including snow, slush, and icy roads.
An "M+S" or "M&S" on the tire sidewall on the other hand indicates it is Mud & Snow Rated, which means it can handle light snow, mud, and off-road conditions, but performance is not guaranteed for severe snow or ice. The symbol is applied through a self-certification process by manufacturers, based on tread design. Typically if a tire has a mud and snow-friendly tread pattern (e.g., larger voids, improved drainage), manufacturers can apply this rating, but unlike the 3PMSF symbol, it does not require specific snow performance testing. Because the M+S rated tires are not as effective in snow, they are commonly found on all-season or all-terrain tires.
What's the safest option for winter driving?
If you’re planning to drive in extreme winter conditions, you should make sure your tires at least display the Three-Peak Mountain Snowflake Symbol (3PMSF) to ensure optimal safety and compliance with regulations in snowy or icy conditions. If your winter driving will be more moderate, an M+S rating will be sufficient. And if you're not sure how extreme the weather might get in the area you're driving to, it's safest to prepare for the worst conditions and opt for tires with the 3PMSF symbol, to get you through that unexpected snow storm.
Read more on related topics in previous blog posts: