Perspective

The ultimate guide to traction tires, chains, and studs

December 11, 2024 by PEMCO Insurance

Heading over a mountain pass over the holidays? Then you've likely thought about traction tires and tire chains recently. While we don't get a lot of snow in many parts of the PNW, the passes can become blizzard-like during the winter and roads can become like an ice skating rink!

You might be wondering, "What are approved traction tires?” And, "Do I really need to chain up when the sign says, 'Chains Required'?” Or, "Are studded tires still a thing? And does 4WD help me on ice?"

Don't worry. We've got you covered.

What are “approved traction tires?”

State departments of transportation often advise or require “approved traction tires” to travel across mountain passes during winter.
Tread depth, pattern and other traction-enhancing characteristics combine to qualify as a traction tire. Here are specifics for Washington and Oregon.
Tires marked with “M+S” (for mud and snow), a mountain/snowflake symbol or “all-season” are approved traction tires.
Studded tires also are approved traction tires.
Adding chains makes any tire an approved traction tire.
Some heavy-duty pickups and large passenger vans fall under stricter rules for vehicles over 10,000 pounds gross weight. In these instances, chains are required instead of just traction tires.

Are all-season tires the same as winter tires?

No. Winter tires are made of softer rubber that grips at lower temperatures, and they have more aggressive tread.
Winter tires typically show the mountain/snowflake symbol.
All-season tires may have the M+S notation.
Because of their softer rubber, winter tires wear out faster (read: expensive). Use them only from Thanksgiving until Easter.

Do I need winter tires?

It depends where you drive and whether you can avoid driving during the worst conditions. If you can avoid driving in ice and snow and don't need to cross mountain passes, then you might be able to get away without them.
All-seasons may be fine west of the Cascades, especially in metro areas that stay mostly above freezing.
Winter tires help in rural and hilly areas, especially if you travel east of the Cascades and cross the passes.

What about studded tires?

Winter tires (without studs) are best for most people in most conditions. They offer better control and stopping power on wet surfaces.
Studded tires are best if you frequently drive on clear ice that’s at or near the freezing point; have a steep, icy driveway or live on a private road that’s not maintained by the city or county.
Studded tires are legal in Washington and Oregon only from November through March because they damage highway surfaces.
Some states have outlawed studded tires to limit road damage. If you’re planning a cross-country trip, check for restrictions along your route.

Does four-wheel drive (4WD) help with winter driving?

4WD helps you get traction when starting out, so you’re less likely to get stuck in muddy or slick conditions.
4WD vehicles tend to have larger tires (more surface area in contact with the road) with deeper tread, which improve traction.
4WD does not help you brake or steer better on ice. It will not help you stop or control your vehicle if you slide.
4WD can contribute to overconfidence among drivers who don’t understand its limitations.

Does “chains required” apply to all cars?

Not always. All-wheel drive and 4WD cars don’t automatically need to chain up as long as all wheels are in gear, they have approved traction tires and carry chains for at least one set of drive wheels.
Studded tires do not count as chains.
All vehicles (including all-wheel and 4WD) must chain up when the reader board says, “chains required on all vehicles.” That’s usually the last step before authorities close a highway because of treacherous conditions or to conduct avalanche control.
Know how to put on chains before you go. This video can help.

NOTE: While we’re experts in loss prevention and home/auto safety, we don’t consider ourselves experts in traffic laws or their enforcement. Information shared here is for educational purposes only and is not legal advice. If you have legal concerns, we urge you to contact a law enforcement source or attorney in your community.