Winter Tires vs All-Season vs All-Weather on the Eastside

Published October 27, 2026By Eastside EuropeanUpdated October 28, 2026

Most people make this decision on price, or on whatever was already fitted when they bought the car. Which is a shame, because the thing that actually separates these three categories is a single symbol on the sidewall — and Washington’s legal minimum does not require it.

That gap is the most useful thing in this article. You can be entirely legal on a Washington mountain pass and still be badly equipped for it.

Here is what the markings mean, what the performance difference actually is, what the law requires, and what is worth buying if you live on the Eastside.

Two markings. Only one of them is a claim about performance.

M+S — “mud and snow” — is based on the geometry of the tread pattern. That is the whole basis of it. As Continental puts it, the performance of an M+S-marked tire is “neither defined nor measured.” Manufacturers can apply the marking at their discretion.

It is a statement about what the tread looks like. It is not a statement that the tire was tested in snow, because it was not.

3PMSF — the three-peak mountain snowflake, sometimes called the Alpine symbol — is earned by passing a test: ASTM F1805, measuring snow traction on medium-packed snow under standardised conditions. A tire has to meet or exceed the threshold to carry it. Winter and all-weather tires produced since 1 January 2018 must carry it.

So the difference is simple and it is the whole game:

M+S tells you what the tread looks like. 3PMSF tells you the tire was measured in snow and passed.

Once you know that, the three categories sort themselves out.

The three categories, properly defined

Type

Marking

What it is

All-season

M+S, usually no 3PMSF

A compromise compound aimed at mild conditions year-round. Competent most of the year here. Hardens and loses grip as temperatures fall.

All-weather

M+S and 3PMSF

The category most people do not know exists. Tested and certified for snow traction, but designed to be left on all year. The compromise aimed squarely at climates like ours.

Winter

3PMSF

A soft compound optimised for use below roughly 45°F (7°C), with aggressive tread and siping. Best by a clear margin in snow and on ice — and the worst of the three in warm, dry conditions.

That last point is not a detail, it is the reason this article does not simply say “buy winter tires.”

The performance difference, including the part that cuts the other way

Comparison testing of braking distances, winter against all-season:

On snow — the all-season needed about 23% more distance to stop
On ice — about 19% more
On cold wet pavement, around 5°C (41°F) — about 9% more

That cold-wet figure is the one that matters most around here, because cold and wet is our default condition for about five months. Nine percent is not dramatic, but it is the difference between stopping at the line and stopping past it.

Now the honest counterpoint. In warm dry conditions the winter tire is the worst of the three. In the same testing, braking from highway speed on dry pavement at around 25°C (77°F), the winter tire needed meaningfully more distance than the all-season — roughly 42 metres against 37. Winter rubber is soft by design, and heat makes it vague, squirmy and quick to wear.

Which is why leaving winter tires on all year is a genuinely bad idea, not merely an uneconomical one. You spend the summer with worse braking than you started with.

What Washington actually requires — and the detail almost nobody knows

This is worth getting exactly right, because the fines are real.

An “approved traction tire” in Washington means a tire with at least 1/8 inch of tread that is labelled M+S, “All Season”, or carries the mountain/snowflake symbol. Fitting approved chains makes any tire count as a traction tire.

The sign levels, in escalating order:

Traction Tires Advised — recommended. Oversize loads prohibited.
Traction Tires Required — all passenger vehicles must have approved traction tires. Chains are required on vehicles over 10,000 lbs GVWR, which includes large passenger trucks, SUVs and RVs.
Tire Chains Required — all vehicles must have approved chains except 4WD and AWD.
Chains Required On All Vehicles — in extreme conditions, everyone fits chains, including 4WD and AWD.

And here is the detail that catches out a remarkable number of drivers:

At the “Tire Chains Required” level, your AWD car does not have to fit chains — but it must still be carrying them. Not carrying them is a violation with a fine attached. The exemption is from installing, not from having.

So the chains in the garage are doing nothing for you. They need to be in the car from November onwards.

Two more:

Studded tires are legal only from 1 November through 31 March. There are no individual exceptions, although WSDOT can extend the date if severe weather is forecast broadly. And studded tires do not satisfy a chain requirement — you still have to carry chains.

The fines: $500 for chain violations, including failing to chain up when required. $136 for running studded tires outside the legal window.

The gap in the law, which is the point of this whole article

Read the legal definition again. An approved traction tire can qualify on an “All Season” label or an M+S marking — neither of which involves any measured snow performance.

So a set of hard, five-year-old all-seasons with 1/8 inch of tread left is a legally approved traction tire in Washington. It will get you past a trooper. It will not necessarily get you up the hill.

Legal and capable are two different standards, and the law sets the lower one. If you drive the passes, buy for the second standard — look for the snowflake, not the label.

AWD: what quattro, xDrive and 4MATIC actually do

Worth being blunt, because this is where overconfidence comes from.

All-wheel drive distributes power to help you accelerate. It does essentially nothing for braking and very little for cornering — both of those are tires, four contact patches, each the size of a hand.

An AWD car on hard all-seasons will pull away from a front-wheel-drive car on winter tires at the lights, and then fail to stop with it at the bottom of the hill. That specific combination — confident acceleration, unchanged braking — is why AWD cars are so well represented in winter ditches.

AWD is genuinely useful. It is just useful at a different part of the problem than the part that hurts you.

The European-car complications

Four things that make this decision more involved on these cars than on a Camry.

1. Large diameters and low profiles. Winter tire availability in 20 and 21-inch sizes is thinner and considerably more expensive, and the short sidewalls that come with those wheels are poor at absorbing the broken, patched pavement winter leaves behind.

2. Which makes a separate winter wheel package the smart move, and often the cheaper one over time. A smaller-diameter winter wheel with a taller sidewall rides better in the cold, grips better, costs less per tire, and keeps your expensive summer wheels out of the salt-brine and pothole season entirely. You will need TPMS sensors for the second set.

3. But a diameter change now has a second consequence. Rolling diameter and ride height feed into the driver assistance calculations, and manufacturers do not validate those systems on wheel and tire combinations they have not sanctioned. Ask about that before buying the winter package, not after — it is a two-minute check against your VIN.

4. Run-flats and staggered fitments. Run-flat winter options are limited, and the stiff sidewall that makes a run-flat work gets harsher as temperatures drop. Staggered setups — wider rears, common on these cars — cannot be rotated and need a correspondingly more expensive winter set. Worth pricing before you commit.

And one rule with no exceptions: never mix tire types across an axle, and preferably not front-to-rear either. On an AWD car, differing rolling diameters between axles can put real stress on the drivetrain. Four matching tires, always.

So what should you actually buy here?

Our honest recommendations by how you actually drive, rather than by what we would like to sell you.

You stay in the lowlands and rarely cross a pass. A good all-weather tire — carrying the 3PMSF snowflake, designed to stay on all year — is the best single answer for most Eastside drivers. One set, no seasonal swap, legally and genuinely capable in the occasional lowland snow, and no summer penalty worth worrying about. This is the category most people have never heard of and most people here should be buying.

You drive the passes regularly, ski, or commute over Snoqualmie in January. A dedicated winter set, ideally on a smaller-diameter wheel package — plus chains in the car from November. The performance gap on snow and ice is large enough that nothing else is a sensible substitute.

Your car is garage-kept, performance-oriented and rarely driven in the cold. Keep the summer or all-season rubber and simply do not drive it in those conditions. A sports car on winter tires is a compromise in both directions.

You commute locally and your all-seasons are sound. You are not doing anything wrong — just know what you are trading. Below 45°F your braking is measurably longer than it needs to be, and if a surprise snow day lands, you will want to leave the car at home.

One last thing, whatever you choose: check the age and the depth, not just the look. Washington’s traction minimum is 1/8 inch, Continental recommends at least 4 mm of tread for genuine winter use, and the date code on the sidewall matters because rubber hardens with age whether or not it is worn. A tire with plenty of tread and six years on it is not a winter tire in any meaningful sense.

Frequently asked questions

What is the difference between M+S and the snowflake symbol?

M+S is based purely on the geometry of the tread pattern — its performance is, in Continental’s words, “neither defined nor measured,” and manufacturers apply it at their discretion. The three-peak mountain snowflake (3PMSF) has to be earned by passing the ASTM F1805 snow traction test on medium-packed snow. M+S describes what the tread looks like; 3PMSF means the tire was measured in snow and passed. Winter and all-weather tires made since 1 January 2018 must carry it.

What are all-weather tires, and are they a gimmick?

No — they are a real and distinct category, and probably the right answer for most Eastside drivers. An all-weather tire carries the 3PMSF snowflake, meaning it passed the same snow traction test as a winter tire, but it is designed to be left on all year rather than swapped seasonally. You give up some ultimate snow and ice performance against a dedicated winter tire, and gain not owning two sets.

Does my AWD car need chains in Washington?

This is the detail that catches people out. At the “Tire Chains Required” level, 4WD and AWD vehicles do not have to fit chains — but they must still be carrying them, and failing to do so is a violation with a fine. At the higher “Chains Required On All Vehicles” level, even AWD vehicles must fit them. Chain violations carry a $500 fine. Keep chains in the car from November, not in the garage.

Can I just leave winter tires on all year?

It is a bad idea rather than merely a wasteful one. Winter compounds are soft by design, and in warm dry conditions they are the worst performing of the three categories — in comparison testing, braking from highway speed on dry pavement at around 77°F, the winter tire needed meaningfully more distance than the all-season. They also wear quickly in heat. Leaving them on means spending summer with worse braking than you would otherwise have.

Are studded tires worth it here?

For most Eastside driving, no. They are legal only from 1 November to 31 March, they do not satisfy a chain requirement so you still have to carry chains, they are noisy and they damage pavement — and on wet or dry road, which is most of our winter, they offer no advantage over a good winter tire. Running them outside the legal window is a $136 fine.

Will a winter wheel package affect my car’s safety systems?

It can, if the diameter changes. Rolling diameter and ride height feed into the driver assistance calculations, and manufacturers do not validate those systems on wheel and tire combinations they have not sanctioned — some require a recalibration after a tire size change. It is a quick check against your VIN, and it is much better done before you buy the package than after.

Deciding before the weather does

Come and talk to us before the first cold snap rather than during it. We will tell you honestly which of the three categories fits how you actually drive, price a winter wheel package against a single set of all-weathers, check whether a diameter change affects your driver assistance systems, and sort TPMS sensors and seasonal storage.

Eastside European Auto Service and Repair has been the Eastside’s dealer alternative since 2010, working on Mercedes-Benz, BMW, Audi, Volkswagen, Volvo, Porsche, Jaguar, Land Rover, MINI and Smart. ASE-certified technicians, over 75 years of combined experience, factory-level diagnostic equipment, and loaner cars available.

Call 425-823-8200 or book online. 12415 NE 124th St, Kirkland, WA 98034. Serving Kirkland, Bellevue, Bothell, Redmond, Issaquah, Mercer Island and Woodinville.