(MONEY Magazine) – Even for seasoned denizens of the snowbelt, white stuff on the ground can mean white knuckles on the steering wheel. But while no one would dream of donning flip-flops to shovel the driveway, many trust their winter safety to vehicles that are just as inappropriately shod. Even consumers who rely on four-wheel-drive vehicles to get them through slick, frigid conditions might be surprised to learn that a less-glamorous technology is much more effective: winter tires. "Four-wheel drive is a wonderful asset for traction to get going, but when you're cornering or stopping, it has no bearing," says Bob Toth, Goodyear's North American tire marketing manager.

Winter tires (formerly known as snow tires) are the best and most overlooked way to improve a vehicle's grip when the weather turns frightful. Tests by Michelin North America proved that today's winter tires deliver 30% more traction on snow than the "all season" rubber that's standard equipment on the vast majority of cars and trucks. In braking tests conducted at 25 to 30 mph, vehicles with winter tires also took four to five car lengths less to come to a stop--potentially the difference between a safe stop and a nasty rear-ender.

For regions where snowfall is sporadic or purely theoretical, consumers are fine with all-season tires. But you don't have to live within spitting distance of the Arctic Circle to enjoy the benefits of winter tires. Freezing rain, sleet and unexpected snowfalls can ambush many regions; winter tires can ensure that you're prepared for the worst. And today's winter tires, developed in the early '90s, have sharply reduced the annoyance of old-school snow tires with their clunky-looking treads and high-decibel hum on dry roads. Sports cars and sport sedans, often equipped with rear-wheel drive and wide performance tires that grip about as well as toboggans in the snow, are prime candidates for winter rubber. Front-wheel and four-wheel-drive vehicles handle noticeably better with winter tires too.

My personal tire conversion came during a trip to General Motors' winter test facility, on a decommissioned Air Force base in Michigan's frostbitten Upper Peninsula. To make things interesting, I tested tires on a Chevrolet Corvette--not necessarily the sled of choice on the tundra.

On its standard Goodyears, the powerful rear-drive Corvette could trudge through ankle-deep snow, thanks largely to its high-tech traction and stability-control systems. But when switched to Goodyear winter tires, this fish out of water became a veritable mountain goat, covering the snow-blanketed course with uncanny poise, faster even than similarly equipped four-wheel-drive SUVs.

THE ALL-SEASON MYTH. For tires, the "all season" name alone convinces people that they're ready for anything from the Sahara to Siberia. But as the label implies, all-season tires must strike a compromise among factors such as dry and wet traction, durability, fuel economy and a quiet, comfortable ride.

Everything that makes all-season tires effective on dry, warm pavement works against them on snow and ice. Their rigid designs and narrow treads nibble at the snow instead of digging in. When all-season tires begin to wear--and many consumers blithely drive tires well beyond their lifespan--their already modest traction in snow is further compromised.

In contrast, winter tires are designed with softer rubber compounds that maintain their grip in freezing temperatures. More important, their deep treads are densely packed with small crosshatchings called sipes. Like the edge of a ski, the thousands of tiny sipes carve deeply into the snow to deliver traction. "The name of the game is how many biting edges you can get into the snow," says Ron Margadonna, technical marketing manager for Michelin North America.

SHOP FOR THE SNOWFLAKE. Many all-season tires display an M&S logo, which stands for mud and snow. But most consumers would be taken aback to learn that there are no traction standards required to earn the designation. To clear up confusion, tire manufacturers in 1999 agreed on a set of criteria for dedicated winter tires. Consumers can now look for the Mountain Snowflake symbol on tire sidewalls to ensure they're specifically designed for slick, snowy conditions. The Michelin Alpin, Goodyear Ultra Grip and Bridgestone Blizzak are all fine choices. Expect to pay $200 to $800 for a set of four, depending on the size and specification. Taller, wider tires designed for high-performance cars cost the most.

Tire experts freely acknowledge the biggest drawback to winter tires: the hassle and expense of switching them every fall and spring. Instead of having tires remounted and rebalanced on your standard wheels, it's simpler to buy a second, inexpensive set of steel wheels for the winter tires. Four wheels will set you back about $120 to $280, depending on size. Many tire shops will store the second set, freeing you from having to clear out space at home.

Because of their flexible sipes, winter tires wear out more quickly than all-season models when they're used on dry pavement. For typical consumers, good-quality winter tires should last at least three winters. But because they wear out faster, don't procrastinate when spring arrives: Switch back to all-season tires as soon as the weather clears.

Lawrence Ulrich is the auto critic for the Detroit Free Press.