All-Season vs All-Weather vs Winter Tires: What Differs

Three tire types, three jobs

Tire makers sort tires used on passenger vehicles into broad seasonal groups. The groups below follow Michelin's definitions. Other makers use similar ones.

All-season tires are built for everyday driving. They balance dry and wet performance and offer acceptable snow traction in regions with light winter weather.

All-weather tires are designed to carry the three-peak mountain snowflake rating. They aim to work in real winter conditions without a seasonal swap.

Winter tires are designed for traction on ice, snow and slush, in addition to wet and dry roads in severe cold.

Summer tires are a fourth group. This guide stays with the three that most drivers choose between for year-round use.

What M+S really means

Most all-season tires have M+S on the sidewall. It stands for mud and snow.

The marking is based on tread geometry. It is not a certified performance test. Continental puts it this way: the performance of M+S marked tires is neither defined nor measured.

That does not make an M+S tire bad. It means the marking alone does not tell you how the tire performs in snow.

What the snowflake symbol means

The three-peak mountain snowflake symbol is a picture of a mountain with a snowflake inside it. Continental calls it the Alpine symbol.

A tire can carry it only after passing a standardized test. Per Continental, winter tires with the symbol go through the ASTM F1805 test on medium-packed snow, to show they meet minimum industry requirements for snow traction.

The test sets a minimum requirement for snow traction. Two tires with the symbol can still perform differently.

All-weather tires are designed to carry the symbol, and winter tires with it are sold too. A tire marked only M+S has not been through that test.

Federal tire marking rules list the Alpine symbol as an optional marking.

Where temperature fits in

Michelin says all-season rubber begins stiffening below 45 degrees Fahrenheit (about 7 degrees Celsius), which can reduce grip on cold, dry roads before any snow appears. Nokian Tyres also says all-season tires are meant to be driven at 45 degrees Fahrenheit and above. Michelin also suggests changing to winter tires when the temperature regularly approaches freezing, typically in late autumn.

For a driver in a mild climate, that may never matter. For a driver where winter roads are regularly icy or snow-packed, it is a reason to look at tires carrying the snowflake symbol.

Choosing between them

Think about the conditions you drive in rather than the label. In general terms:

All-season tires are aimed at drivers who see mostly dry and wet roads and light winter weather.

All-weather tires are aimed at drivers who see regular winter weather and do not want to store and swap a second set. They are a middle ground between the other two.

Winter tires are aimed at severe cold, ice and snow. That is the job they are designed for.

If you are unsure which group fits your area, a local tire professional can tell you what drivers nearby choose.

Tread depth matters too. Continental recommends winter tires with the Alpine symbol and at least 4 mm (about 5/32 inch) of tread depth for winter driving. Our guide to when tires need replacing explains how to measure tread.

Local rules differ. Colorado, for example, can activate a Traction Law or Chain Law on state highways during winter storms. Under a Chain Law, every vehicle must have chains or an approved alternative traction device. Check your state or province before you travel.

What to look for on the sidewall

You can sort most tires by looking at the sidewall.

Look first for the snowflake symbol. If it is there, the tire passed the snow traction test. If you see only M+S, the marking reflects tread design and not a test result.

Then look for the UTQG grades. The federal grading rule does not apply to winter-type snow tires, so those fields may be blank on a winter tire. Our guide to UTQG ratings explains the exemptions.

Finally, read the size, load index and speed rating. Our guide to reading a tire sidewall shows how.

Questions worth asking a tire professional

A shop that sees local winters can answer questions a general guide cannot.

• How often do roads in my area stay snow-packed or icy?
• Does my vehicle's maker specify a tire type or size for winter use?
• If I buy a second set of wheels, how will it be stored and swapped?
• Should I choose the snowflake symbol for my daily driving?

You can use the answers to narrow the choice before you shop.

Fit them as a set

Michelin states that winter tires are engineered to work as a complete set. Installing them on only one axle creates a traction imbalance between front and rear, and the vehicle can react unpredictably when road surfaces vary.

Michelin also advises that every tire on a vehicle should match in size, type, speed rating, load capacity and construction. See our guide on replacing two tires or four for how this works when only some tires need replacing.

Check the size first

Seasonal tires are bought in the same size format as any other tire. If you are not sure of your size, read it from the tire sidewall or the driver's door placard, then use the tire finder to see what is available in that size.

Some drivers buy a separate set of wheels for winter, and then the size can differ from the summer set.

Before you change size, compare the two with the tire size calculator, which shows diameter and speedometer difference. Then confirm the choice with a tire professional or your owner's manual.

Common sizes that appear on our size pages include 225/65R17 and 235/65R17. These are examples of how sizes are listed, not a statement about what suits your vehicle.