M+S against the three peak mountain snowflake
Two winter markings that look like a pair and are not. One describes a tread pattern. The other reports a measured result.
Side by side
| M+S, M&S, M/S | Three peak mountain snowflake | |
|---|---|---|
| Awarded on | Tread geometry | A snow traction test |
| Is a tire driven on snow to earn it? | No | Yes |
| Threshold | No performance threshold | At least 110 percent of a reference tire on medium packed snow |
| What is measured | Nothing is measured | Acceleration traction only |
| Covers braking on snow? | No | No |
| Covers ice? | No | No |
M+S
M+S, M&S or M/S means mud and snow, and it is awarded on TREAD GEOMETRY alone. No tire is driven on snow to earn it and no performance is measured. Most all season tires carry it. It is a description of a tread pattern, not a winter capability.
The three peak mountain snowflake
The three peak mountain snowflake is earned by testing. The tire has to deliver at least 110 percent of a reference tire's traction on medium packed snow, which is a 10 percent margin over the baseline, before it may carry the symbol. That is a real threshold, and it is why the symbol and M+S are not interchangeable.
What the snowflake does not cover
What the symbol does NOT cover: the test measures acceleration traction on medium packed snow. It does not test braking, it does not test cornering, and it does not test ice at all. A tire carrying the symbol can still be well short of a dedicated winter tire on an icy road.
Common questions
- What is the difference between M+S and the three peak mountain snowflake?
- M+S, M&S or M/S means mud and snow, and it is awarded on TREAD GEOMETRY alone. No tire is driven on snow to earn it and no performance is measured. Most all season tires carry it. It is a description of a tread pattern, not a winter capability. The three peak mountain snowflake is earned by testing. The tire has to deliver at least 110 percent of a reference tire's traction on medium packed snow, which is a 10 percent margin over the baseline, before it may carry the symbol. That is a real threshold, and it is why the symbol and M+S are not interchangeable.
- Does the snowflake symbol mean the tire is good on ice?
- What the symbol does NOT cover: the test measures acceleration traction on medium packed snow. It does not test braking, it does not test cornering, and it does not test ice at all. A tire carrying the symbol can still be well short of a dedicated winter tire on an icy road.
- Is an all season tire with M+S enough for winter?
- M+S on its own tells you about the tread pattern and nothing about measured snow traction. Where winter conditions are severe, or where local law specifies a marking, the three peak mountain snowflake is the marking that was earned by test. What is adequate depends on the conditions and the law where you drive, which this site cannot know.
- Can a tire carry both markings?
- Yes, and many do. The snowflake usually sits next to the M+S lettering on the sidewall. The two are awarded on different bases, so carrying both is normal rather than redundant.
Where these figures come from
Published values here were read from 3 independent sources:
- Tire code - Wikipedia, revision read 27 August 2026 (read 2026-08-27)Load range letters and ply ratings, M+S definition, sidewall marking glossary
- What the 3PMSF Symbol Means for Winter Driving Safety - Les Schwab, undated reference article (read 2026-08-27)3PMSF meaning, the medium packed snow test, what the symbol does not cover
- What Is the 3PMSF Symbol and How Does It Affect Your Tires - DuallyWheels, undated reference article (read 2026-08-27)3PMSF test standard and the 110 percent traction index threshold, M+S comparison
These are independent publishers, not independent measurements. Each one reproduces a table originally set by a standards body, so agreement between them shows a value was transcribed correctly, not that the underlying table is right. Where a figure is safety relevant, check it against the tire manufacturer's own data before relying on it.