M+S Tyres vs 3PMSF: Marking Meaning Explained (2026)

M+S vs 3PMSF tyres (tires) at a glance

Figures in this table are according to Transport Canada and the Government of British Columbia (see Sources).

M+S means mud and snow. The tread is shaped to handle some mud and light snow, but a manufacturer can print M+S without any snow test. 3PMSF, the three-peak mountain snowflake, means the tyre passed a standard traction test on packed snow. If a law or a mountain-pass sign asks for winter tyres, a 3PMSF tyre is the safe choice.

What M+S means on a tyre

M+S is a marking for tread design, not a performance rating. It shows the tread has wider grooves and more open blocks than a summer tyre. That is why almost every all-season tyre sold in North America has it. Tyre shops often call these “mud and snow tires”, but the name does not mean the tyre has been tested in snow.

The M+S letters say nothing about the rubber compound either. A tyre built mainly for warm, dry roads can carry M+S as long as its tread pattern fits the design definition. Canada’s tyre industry says it plainly: an all-season tyre without the mountain snowflake does not meet the snow traction requirements for a winter tyre.

What the 3PMSF symbol proves

The symbol is a mountain with three peaks and a snowflake inside it. Under Canada’s Motor Vehicle Safety Regulations, a winter tyre must be traction-tested on medium packed snow. It needs a traction index of at least 110 against a reference test tyre, which means 10% more grip. The manufacturer certifies that the tyre passes, and only then may it print the alpine symbol.

Canada and the United States developed this standard together, and according to Transport Canada the two countries’ standards are now fully aligned, so the symbol means the same thing on either side of the border. Canada has had minimum winter-tyre requirements since 1999, and the test was made stricter in 2013.

The limits matter. 3PMSF is a test on snow only. Some manufacturers advertise how well their tyres grip on ice, but Canada, the US and the EU have no government standard for ice performance. A 3PMSF all-weather tyre and a dedicated winter tyre can both pass the snow test and still perform very differently on ice or on very cold, dry roads. Our all-season vs winter tyres comparison explains the difference.

Why a tyre can carry both markings

The two markings measure different things, so they can appear side by side. Most winter tyres have both. British Columbia’s government notes that some manufacturers label tyres with both the mountain snowflake and M+S. When you check a tyre, the snowflake decides whether it counts as a winter tyre, not the M+S. Both markings sit on the sidewall near the size code. To read the rest of that code, use the tyre markings guide or the tyre size calculator.

Which marking the rules ask for: Canada, the US, the UK and Australia

Canada. Each province and territory decides whether winter tyres are required. Quebec is the only one with a mandatory province-wide rule for the winter season. Before driving there in winter, check Quebec’s current rules for the symbol and the dates. British Columbia accepts M+S as the minimum legal winter tyre, or the mountain snowflake, with at least 3.5 mm of tread. Most B.C. routes require winter tyres or chains from October 1 to April 30. On some highways that don’t cross mountain passes or high-snowfall areas, the requirement ends on March 31. Drivers who don’t comply can be turned back and fined. Even so, the province recommends mountain snowflake tyres for cold-weather driving and chains for extreme conditions.

United States. The snowflake test is the same as Canada’s. Rules on chains and traction devices are set by each state and can change with the weather. Check the state’s transport department before you cross mountain passes.

UK and Australia. Visitors driving abroad in winter need to check the rules of the country they’re driving in. Some European countries that require winter tyres accept only the alpine symbol, so a hire car with M+S-only tyres may not be legal there. Check each country in the winter tyre laws by country guide. Where studs are allowed, see studded tyres by country. In alpine areas, neither marking replaces chains where signs require them.

What to do: keep, swap or rent with 3PMSF?

• Your tyres show M+S only and you drive in regular snow or below-freezing weather: treat them as all-season tyres. They are not winter tyres, even where they are legal.
• You are driving in Quebec, or in European countries that require the alpine symbol: fit tyres with 3PMSF. M+S alone may not meet the rule.
• You are driving B.C. mountain routes: M+S with at least 3.5 mm of tread is the legal minimum. 3PMSF tyres plus chains are what the province recommends.
• You want one set of tyres for the whole year: look for an all-weather tyre with 3PMSF. It passes the same snow test as a winter tyre, but it is not tested on ice.
• You are renting a car: ask for 3PMSF tyres when you book. Before you drive off, check the sidewall for the mountain snowflake symbol, not just M+S.
• Your tread is worn close to 3.5 mm: on B.C. winter routes, the tyre no longer counts as a winter tyre, whatever its marking.

For picking and fitting a winter set, see the winter tyre guide 2026. To compare tested options, see best winter tyres 2026.

Sources

• Transport Canada: Winter Tires (briefing document): the snow traction test, the traction index of 110, alignment with the US standard, no ice standard.
• Government of British Columbia: Passenger Vehicle Tire and Chain Requirements: M+S and mountain snowflake markings, 3.5 mm minimum tread.
• Government of British Columbia: Designated Winter Tire & Chain Routes: October 1 to April 30, March 31 on some highways, enforcement.
• Continental Tire Canada: Winter tire markings: M+S and 3PMSF as sidewall markings.