Flashbacks to my misspent youth come flooding in as I grab a chair in one of Notre Dame hockey team's classrooms. Just a few steps away, a pair of sedans are staged in front of a drag racing Christmas tree out on the team's ice rink. Taken at face value, by a native Southern Californian, that scenario appears to be fraught with peril. I don't know how fast we'll be going, but there isn't a whole lot of space left after going through the traps to get these cars down from any speed on a sheet of ice.
My own superior climate of choice aside, I'm here to learn; and the lesson plan that's in store for me is likely going to prove crucial for a wide swath of North America in the coming months. "A lot of drivers wonder if winter tires are really worth the added expense," says Tire Rack's Woody Rogers. "Well, we wouldn't be here if we didn't think so."
But both Michelin and Tire Rack have an uphill battle to climb in this regard. Less than ten percent of drivers who live in North American regions that experience what they classify as "severe" winter driving conditions actually swap over to winter tires during the months when those tires are needed—roughly from Thanksgiving to tax time. With very few OEMs offering factory-installed winter tires, the responsibility falls on consumers to ensure their vehicles are equipped with the proper footwear for the season.
For the vast majority of drivers, that translates to running all-season tread throughout the year. "All-seasons are designed to provide balanced performance in light to moderately bad weather conditions," explains Michelin's senior technical manager Ron Margadonna. "But when the driving conditions get really bad, the design optimizations in winter tires become very clear."
Winter Tires vs. All-Seasons
It's not hard to see why advocates of winter tires have their work cut out for them. Most drivers assume simply by virtue of the naming contention that all-seasons provide year-round capability. They're also designed to perform their best in cold weather conditions of 44 degrees Fahrenheit or below—the same temperature specification applied to winter tires. That makes the choice somewhat nebulous for the uninitiated, and when presented with a path that presumably requires less time and expense, the vast majority of buyers will opt to run one set of tires year-round.
There's a reason that the 3PMSF (3 Peak Mountain Snowflake) certification exists and is applied to winter tires which meet that safety standard. "This is where consumers can easily differentiate true winter-capable tires from all-seasons," says Margadonna. It's not simply a matter of tread patterns that are more attuned to handling snow and ice though, as modern winter tires feature unique designs right down to the molecular level that is specifically geared toward the sustained low temperatures and low-friction scenarios that drivers face during harsh winter weather.
Using Michelin's X-ICE Xi3 (passenger car) and Latitude X-ICE Xi2 (light truck/SUV) tires as examples, Michelin's technical communications director, Tom Carter, walks us through winter tire design, which starts with a full-silica rubber compound which is purposely designed to maintain its flexibility in below-freezing temperatures. "Michelin began putting silica in tires to bring the glass transition temperatures down," he explains. "That 'glass transition point' is the moment when something flexible like rubber essentially becomes a solid."
We're later shown three compound samples (summer, all-season, and winter) that have been attached together and have spent some time out on the ice rink. The summer compound is essentially frozen stiff. The all-season fairs better—but not by much—and is pliable with some effort, while the winter compound appears completely unaffected by the cold temperatures and bends without effort. Maintaining consistent with the ground is obviously of paramount importance where traction is concerned, so if your tire isn't willing to easily conform to the ground surface its grip levels will inevitably drop.
The tread pattern itself is of course a key component as well, and features design elements like "micro pumps" which force moisture away from the tread surface while the tire's aggressive block edges are designed to bite into ice and snow to create a friction point to enhance traction.
That all sounds well and good on paper, but how will it translate in practice? To answer that question we head out to our ice rink drag strip, where a pair of Kia Cadenza sedans have been outfitted identically, aside from a set of Michelin all-seasons on one vehicle and Michelin winter tires on the other. The "race" measures 60-foot acceleration times between the two vehicles with all driving aids on. My best run on the set of all-seasons was a glacial (pun intended) 8.77 seconds, while the winter tires fared significantly better at 5.5 seconds.
More than anything it showcases how little available grip there is on icy surfaces, and how every bit of help is sorely needed—it still takes several car lengths to slow both cars down from trap speeds that couldn't be more than 10 mph, though it is clear that the car outfitted with winter tires is far more willing to slow down with any semblance of urgency.
Is All-Wheel Drive Enough?
"Many drivers tell us, 'I have all-wheel drive, so I don't need winter tires,'" says Rodgers. "But in severe winter conditions, that is flawed thinking." To illustrate this we're brought to another rink where they've set up a pair of AWD Kia Sportage crossovers, similar to the sedan drag race test earlier, with all-season tires on one and winter tires on the other. Here we're instructed to race to the line as well, but what's measured is trap speed and braking distance from that point.
The results take a bit of processing—the winter tires actually take longer to stop at 64 feet during my run versus 51 feet in the all-season-equipped Sportage, but that's because the winter tire vehicle is crossing the line at 17 mph while the all-season-clad CUV only hits 12.6 mph before I slam on the brakes.
The point is made more obvious driving on a handling course around the rink, where the all-season vehicle loses grip and understeers straight into a set of cones at just 10 mph while negotiating a corner. The winter tire vehicle takes that same corner at identical speed without issue. Scientific? Not really. But it does illustrate the difference in capability quite clearly.
A Visit To the Tire Rack
You might wonder why Notre Dame was chosen as the location for these tests. Along with giving us a chance to check out the newly revamped stadium, the school is also within close proximity to Tire Rack's headquarters in South Bend, Indiana. Besides serving as the company's main distribution center, it's also where the company performs their wet and dry handling tests.
"This is a company founded by enthusiasts," says Tire Rack's executive vice president, Matt Edmonds. "Racers were getting tired of waiting weeks to get tires and we wanted to fix that. But we also wanted to do things differently from an informational standpoint too, and provide our customers with the knowledge needed to make informed buying decisions."
After checking out the various facilities of the massive million-square-foot distribution center we headed out to the test track, where 80 sprinklers were dousing the pavement with more than 400 gallons of water per minute for our wet handling tests. After getting a few scouting laps in with tips from one Tire Rack's resident test drivers, we were set loose to explore the limits of wet handling grip in a pair of identically equipped BMW 430i sedans outfitted with all-season rubber.
Essentially every type of tire that's sold through Tire Rack's facilities is put through its paces on this autocross-like road course, giving the company the unique ability to evaluate tires in a highly controlled environment under fairly repeatable circumstances. "We've collected about two and a half billion miles of data related to tires currently on sale here," Edmonds tells us. "We're always thinking about tires so our customers don't have to."