Wyatt Knox from Team O’Neil lays it out in no uncertain terms: “Winter tires are a complete no-brainer in this day and age: tests have proven that two-wheel drive cars equipped with winter tires consistently outperform all-wheel drive vehicles with all-season tires in winter conditions. Quality winter tires will give you the best possible advantage to getting through the winter unscathed.”

Car Talk Says: If you really, truly need to get around before the streets are plowed, four top-quality winter tires are the single best thing you can get. The reason you'd you want them-- even if you have all-wheel drive-- is that they not only help get you started, they also increase your traction when braking and turning.

To illustrate the point, Tire Rack runs the RAV4 to 10 miles per hour on the ice. With four Blizzak DMV2s, the RAV4 stops seven feet shorter, approximately half a car length. At just 30 miles per hour, the tires alone translate into stopping 56 feet shorter. That’s about three and a half car lengths.

It’s the same story with the Camry. At 10 miles per hour, the WS80-equipped Camry stop eight feet shorter than with all-season tires. At 30 miles per hour, it’s a 63-foot difference.

To get a sense of those tests, we talked to one guy who performs them, year in, year out, to figure out which winter tires are best suited for what conditions. Matt Edmonds is a vice president with Tire Rack. Along with being a massive retailer of tires via the internet, Tire Rack does a tremendous amount of testing to provide customers with the things they need to know before they buy. Some of that testing occurred just last week at a pair of skating rinks near its facility in South Bend, Indiana.

“We had two vehicles on two sheets of ice,” Matt told us the day after testing. “We typically use a BMW 328i because BMWs tend to stay consistent throughout the life of the vehicle, and they also accept a wide range of wheel diameters. For this test, though, we used a current Toyota Camry and a Toyota RAV4.”

By having a front-drive car and an all-wheel drive car, Tire Rack can show how something other than an all-wheel drive vehicle can stop and turn more effectively than an all-wheel drive vehicle with the proper tires mounted.

Both test vehicles made runs on the ice with the tires they were equipped with from the factory, and FOUR Bridgestone Blizzak tires (a note on that later). The Camry received the Blizzak WS80, and the RAV4 got the Blizzak DMV2. The DMV2 utilizes the WS80’s same winter compound, but it has a tread and a carcass more appropriate for SUVs and CUVs.

Winter tires have changed dramatically since the Blizzak was introduced in 1988 when Japan outlawed the use of studs in snow tires. In recent years, studded tires have been similarly banned in 11 states (Alabama, Florida, Hawaii, Illinois, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Texas, and Wisconsin, and Maryland only allows studs in some counties). Studded tires are prohibited in Ontario, but permitted in all other Canadian provinces, typically between October and the end of April.

Studs were effective on ice, but they had a lot of drawbacks during the 90 to 95 percent of time drivers are on dry or wet pavement, according to Tire Rack’s Matt Edmonds. “Studs are uncomfortable, noisy, and they really have worse driving characteristics when it’s not actively snowing or icy,” he says. “Plus, they’re hard on roads and represent an environmental issue with increased dust and debris.”

Ron Margadonna, Senior Technical Marketing Manager from Michelin North America, stresses that there’s a distinct difference between “snow tires” and “winter tires.” “Snow is only one element you’re presented with during the winter,” he says. “Twenty-five years ago, ‘snow tires’ were knobby and had big lugs and big voids between those lugs.”

The difference between modern winter tires and those old snow tires is night and day, in the ratio of rubber on the road, and the chemistry of the rubber. Think of rubber ratio in terms of a racing slick. They have a 100 percent rubber ratio. Snow tires from the 1980s and 1990s could have a rubber ratio of 65% rubber, 35 percent void between the rubber blocks.

“Modern winter tires have a 70/30 rubber to void ratio,” says Michelin’s Ron Margadonna. Tires like the Michelin’s X-Ice and Latitude X-Ice have a more aggressive tread pattern and tread blocks that are open and aggressive to dig through the snow to the pavement below. In addition, individual tread blocks are heavily siped, meaning they have a zig-zag pattern sliced into each tread block that allows the block to move and conform to the road below, digging through the snow. Siping provides many more biting edges.

“We traded the voids for more functional rubber. That’s the single most important evolution in winter tires since about 2001: developing a rubber compound that offers maximum traction at temperatures well below freezing,” says Michelin’s Margadonna. “Those compounds maintain their flexibility as temperatures drop below 32 degrees. Compared to all-season tires, they give more grip in colder temperatures.”

Tires like the Michelin X-Ice aren’t designed for just snow. They’re designed for what Ron Margadonna calls ‘white road’ and ‘black road’ conditions. White road would be roads covered with snow and ice. Black roads would be everything else you face in the winter months: cold, wet, dry, freezing rain, sometimes all in the same commute. The stuff that makes winter so completely unpredictable.

Finally, the rubber compound that winter tires use alone provides a much greater advantage compared to summer or all-season tires. “Winter tire compounds work in the coldest temperatures,” says Matt Edmonds. “They’re designed to stay soft at 40 degrees and below, where all-season tires need to work between about 20 degrees and 110 degrees. In cold temperatures, all-season tires get much harder and are less able to mate to the pavement. At 40 degrees or lower, summer tires become almost plastic-like.”

Inside the rubber, winter tires have micropores in the compound. When warm tires cut through snow, they melt the snow into a thin film of water, which is what makes snow and ice so slick. The micropores give someplace for that water to go. “The latest generation of winter tires have a hydrophilic coating that actually sucks water into the tires,” says Matt.

The final consideration is diameter. Instead of having to mount and dismount winter tires, you can get a winter wheel and tire package that allows you to just swap wheels every winter. That opens up the option to select a smaller diameter, which allows for more sidewall. Anyone who has lost a tire in a late winter pothole can appreciate that bit of extra cushion. Increasing the sidewall maintains the size of the air chamber in the tire, while simultaneously allowing the tire to be narrower, reducing the opportunity for a wider tire to “snowshoe” or float on the surface of the snow, rather than biting into it.

Car Talk Says: Because it's such a pain to get your winter tires remounted and balanced every year, splurge and get yourself four steel rims—maybe even used ones from a recycler-- and mount the winter tires permanently on those rims. That'll make the changeover in the fall and spring a snap.

How do you identify a winter tire? Michelin’s Ron Margadonna points to the symbol on the tire’s sidewall. “Just before the turn of the millennium, the tire industry realized that there wasn’t a consistent way to identify a true winter tire,” he says. The M+S [for Mud and Snow] marking appeared on all-season tires, which was originally designed to describe the geometry of the tread design. But as winter tires evolved into their own class, the M+S designation was confusing . If it says “snow” right on it, isn’t it a winter tire?

So the industry developed the “mountain and snowflake” symbol to indicate that these modern winter tires not only had a more aggressive tread pattern than an “all-season” tire, but also had a winter-specific rubber compound. “Tires carrying that symbol are designated for severe winter duty,” says Margadonna.

Most people who refuse to switch to winter tires provide the argument that winter tires have a negative effect on fuel economy, but, according to Matt Edmonds, most people are experiencing fuel mileage penalties because they’re not monitoring their air pressure. “From 70 to 40 degrees, you can be down three PSI in every tire in a matter of days,” he says.

The US Department of Energy also suggests that fuel economy can be 12% lower at 20 degrees F than at 77 degrees F. (There are multiple reasons for that we’ll talk about in Chapter 5.)

Car Talk Says: If it's -10 now, and the last time you checked your tire pressure was back during that sweltering heat wave in July, your tires’ air pressure can be as much as ten pounds low, which will jeopardize your car's handling. Don’t forget to reverse the process come spring, too!

The fuel economy difference might be something you recognize in the winter, but it’s got little to do with the tires on your car.