What You Need To Know About Winter Tires

Back in the day, snow tires were called that for a very good reason: Unless the road was covered in snow, they were terrible.

Snow tires were sloppy handling and near-grip-free on dry and, especially, wet roads. A single emergency stop in the dry would ruin the tire's tread. Twenty years ago, as a test driver for a major magazine, I ripped whole tread blocks from a snow tire's tread in a single dry-road antilock brake (ABS) emergency-style stop. And that stop was roughly a third longer than the vehicle's original-equipment all-season tires took to stop.

Later, as a test driver for a tire company, I found emergency stopping distances in the wet were sometimes hard to measure: A vehicle equipped with snow tires would still be moving as the wet test surface was about to end.

That was then. This is now.

"If you've never driven on modern top-quality winter tires, it's hard to describe the feeling of liberation you get when you switch from half-worn original-equipment tires to new winter tires," says Woody Rogers, product information specialist for Tire Rack.

"With top-quality winter tires you're no longer at the mercy of the weather or drivers around you," he says. Further, quality winter tires give up almost nothing to original equipment all-season tires in emergency performance on dry roads or in the rain, Rogers says.

Those who live where the average yearly snowfall is 350 inches are in tune with modern winter tires, especially when they run a snow and ice driving school.

"It's eye-opening what winter tires will do today," says Mark Cox of the Bridgestone Winter Driving School in Steamboat Springs, Colorado. "The best winter tires will sometimes squeal a little on glare ice during an emergency-style stop."

Good for Wet, Cold Snowless Roads, Too
There's also little compromise with winter tires if the weather is cold or wet but the roads are snow-free.

On such roads, top-quality winter tires are almost as good in emergency stopping and cornering as original-equipment all-season tires, says Rogers, who also does testing for Tire Rack.

In a recent test of winter tires, Rogers says, he used an original-equipment all-season tire as the baseline, just to limit wear on the winter test tires. "I was shocked when the winter tires came within a few feet of matching the all-season tire," he says.

"Years ago," he says, "the wet stopping test with snow tires was sometimes like, 'Whoa, are we gonna stop before the guardrail?' Today, if you buy top-quality winter tires you sacrifice very little as compared to an original-equipment all-season tire when the temperature drops below 40 degrees."

Rogers is referring to the fact that the tread rubber on winter tires is designed to excel when the ambient temperature drops below about 40 degrees Fahrenheit. Tire engineers call it "glass transition temperature."

As the thermometer falls, rubber stops being pliable. The rubber on winter tires, however, is designed to remain supple at incredibly cold temperatures. But that performance comes with a price: When the temperature rises, the tread on winter tires wears quickly and performance falls far short of all-season tires.

Stepped-Up Handling
Stopping power isn't the only thing that has improved in winter tires. Handling is better as well.

Snow tires were known for "squishy and imprecise handling" 25 years ago, Cox says. "They gave little feel and broke traction on dry and wet roads with little warning and almost no chance of recovering the skid."

Today's top-quality winter tires feel like all-season tires and offer about the same handling characteristics, he says. The handling characteristics are significant because every new passenger vehicle is equipped with electronic stability control (ESC).

Consider ESC a computerized version of a racecar driver: It "feels" the tires beginning to break traction and takes action designed to prevent the vehicle from spinning out or plowing straight off the road. The ESC will work better if the tire provides the same feedback and opportunity for recovery that would please a racer.

More good news: While increasing dry- and wet-road performance, winter tires are a lot better in the snow than were previous-era snow tires. "Every year I see improvements in traction on snow and ice," Cox says. "Not giant breakthroughs, but constant progress."

What's it feel like to replace top-quality all-season tires with the best modern winter tires? In this writer's experience, it's as if the snow-covered handling track suddenly turned into dry pavement.

Pick Top-Quality Tires
It is important to select a top-quality winter tire, says Tire Rack's Rogers. "The best winter tires are offered by Bridgestone, Michelin and Continental," he says. "Some of the other brands don't offer nearly the same performance."

Cox agrees with Rogers: "Those three brands are the 1,000-pound gorillas of the winter-tire world." What sets those brands apart, essentially, is the amount they spend on research and development and on employing extremely skilled engineers.

To know which tires are best, read reliable reviews such as those from Edmunds, Tire Rack and Consumer Reports (a subscription may be required). Expect to spend from $150 to almost $190 per tire, installed, for top-quality brands.

When To Install Them, When To Retire Them
While the tread life of winter tires has improved dramatically, it's not smart to wear out their rubber in hot months. So when should you install winter tires?

"When you can see your breath in daytime," says Cox. Rogers, whose company is based in northern Indiana, uses a calendar approach: "Install winter tires around Thanksgiving and take them off at tax time."

Also, winter tires should be permanently scrapped well before you'd consider retiring conventional tires. As with most passenger vehicle tires, winter tires start with 11/32-inch deep tread. By the time winter tires are down to a tread depth of 6/32-inch, they have lost almost all of their capability.

"At 6/32nds they're just nibbling at the snow," says Rogers. "They were taking great big bites when they were new."

When winter tires reach 5/32-inch deep tread, they will look barely worn to most people. But at that point, they should be on their way to the recycling center, Rogers says. Tread-depth gauges are not available in many auto-parts stores, but they're about $6 on Amazon. Also, good tire stores will gladly measure your tread.

Are Winter Tires for You?
If you wonder whether to get winter tires at all, listen to snow-driving instructor Cox: "Some people can go a year, or even lifetime, and never seriously lose traction on dry or even damp roads," says Cox. "And it's a really big, scary deal if they do."

But in places where the snow really comes down and ice is an everyday thing for several months a year, the average driver will step over the "grip limit" multiple times on the way to work or school. (Studies have shown that people radically underestimate grip on dry roads and radically overestimate it in the snow.) Each one could be an accident waiting to happen. And that's why you should give winter tires your consideration.