We'll keep this simple. If you live in the snowbelt and you're running all-season tires year 'round, you're probably sacrificing a noticeable level of vehicle control and performance when driving on snow and ice. Yes, it's become fashionable in the U.S. to rely on all-season tires in, well, all seasons. When winter rears its ugly head, though, even the best all-season designs won't be able to match a quality winter tire on snow and ice.
Blizzak M2-02
The reason is also simple. All-season tires are a compromise: You don't expect them to deliver the same cornering potential on pavement as dedicated performance tires, and likewise, they can't match the slippery-road traction of today's winter tires. "The difference between an all-season tire and a snow tire," notes Matt Edmonds, director of marketing for The Tire Rack, "is the same as between an all-season tire and a performance tire. It's that much better."
More Europeans seem to have gotten the message. According to statistics provided by Goodyear, for instance, about 80 percent of drivers in Scandinavia switched to dedicated winter tires during the "dark months." About half of Austrian and Swiss drivers and nearly one-third of German car owners also mount up winter tires when the weather turns cold.
In terms of sheer traction, studded tires still provide the best grip. Goodyear estimates that a metal-studded tire provides up to 40 percent greater traction on hard-packed snow and ice than all-season tires. However, they also have a definite downside, producing higher noise levels, decreased ride comfort, and reduced traction on both dry and wet (but non-freezing) road surfaces. Plus, they're well known for chewing up asphalt, leading many regional governments to ban their use.