All-Season Tires Aren't
How many wrecks have been caused by the tire industry's insistence upon the term "all-season" for tires that are terrible in winter and merely adequate during spring, summer, and fall? We'll never know the answer, but it's a question that struck me on a drive home last weekend during which I encountered numerous snow squalls and a mix of road conditions from dry pavement to spotty icing to a complete coating of newly-fallen snow. Winter tires on my vehicle provided a level of confidence and safety that I had not realized possible until a few years after moving to the Upper Peninsula.
My parents ran studded winter tires. I remember my dad swapping them onto our car each winter.
Studs were banned in Michigan in 1972. Then came the rise of so-called "all-season" tires beginning with the Goodyear Tiempo in 1977. That was the year I began to drive, and I fell prey to the belief that "all-season" meant what it said. I endured many a harrowing winter's drive as a result of wrongly trusting in the promise of an all-season solution that really is a no-season compromise.
Put aside thoughts of SUVs and four-wheel drive. The number one thing you can do to improve your safety during winter driving is to invest in a good set of four tires designed for driving in cold, ice, and snow.
Don't be fooled by summer- and mud-tires with deep tread patterns like are often found on SUVs and trucks. If you aren't running a winter rubber compound, then you have no advantage. The advantages of winter tires begin with the right rubber for the right temperature:
- Winter rubber compounds maintain good contact with the road surface by being soft and pliable during cold conditions. This brings tremendous advantage.
- Winter tread designs include generous grooves and siping by which to expel snow and slush efficiently, enabling the tread to maintain contact with the underlying road surface.
- Winter tires and tread patterns are built with other technical features and materials to enhance traction and grip in cold and slippery conditions, and on snow and ice.
- Winter tires provide significant advantage even on dry roads, in cold weather. They are not just about snow, but also about proper traction in cold conditions.
- Similarly winter tires are a disadvantage and give reduced traction in warm weather. Do not think you gain traction in summer from a winter tire with its deep tread pattern; you don't.
- Always buy four! It is a big, hairy, dangerous error to run winter tires on only two of your four wheels.
Tire Rack is a company making a big business in winter tires. Tire Rack does a lot of testing, and their winter tire page is an excellent resource leading to all sorts of good information and test results. Also chock full of good information are Tire Rack's Winter Tire FAQ and Winter Tire Tech pages.
Recognize winter tires by the mountain and snowflake symbol. That symbol on your tires is what you want during winter. Don't settle for less.
Tire design is ever an exercise in finding a sweet spot of compromise between conflicting priorities, and even within winter tires there can be subtly different priorities at play. The above images show two tread patterns that I have personal experience with. The Michelin X-Ice Xi3 tires prioritize low rolling resistance and my experience puts them as a good choice for vehicles driven mainly on plowed roads and on cold and dry pavement. The Bridgestone Blizzak WS-70s are more surefooted in deep slush and deep snow, but I don't like them so much on cold and dry pavement where they wear quickly and roll with more noise. But the difference between them is nothing compared to how much better they both are as compared to any all-season tire in winter-driving conditions.
All-season tires ought to be termed three-season tires, and perhaps even better would be to term them as non-winter tires so as to discourage their use in the one season to which they are most ill-suited. If you live where it's cold enough to own a pair of gloves during winter, then consider investing in a good set of winter rubber for your car. You'll thank me later.