The new Ice Grip Symbol on the sidewall of a Nokian tire next to the three-peak mountain snowflake symbol for winter tires.Courtesy of manufacturer
Winter is coming if it has not already arrived where you live, and for most Canadian motorists who drive though snow and ice, it’s smart to have winter tires. But are those tires good enough?
Until recently, there have been two official grades of winter tire, with their identification stamped right on the sidewall: “mud and snow” (M+S) and “three-peak mountain snowflake” (an outline of a mountain with a snowflake in the middle). M+S tires have no actual requirements aside from the manufacturer’s own classification; there are no official tests of their abilities. They were introduced in the 1970s with generally blockier tread, more capable of dispersing snow and mud than the ribbed tires of the time. The symbol is often found on all-season tires.
Mountain snowflake tires were introduced in the 1990s as a true winter tire, with softer rubber that has more grip on cold pavement, and a more aggressive tread for better traction on snow and ice. They existed in some form long before they were classified as such, but the symbol on the sidewall is a guarantee that they’ve passed testing sanctioned by the International Organization for Standardization (ISO) to be certified for winter use.
Manufacturers and driving experts recommend that if you drive in temperatures below 7 degrees Celsius, you should switch to winter tires for better grip. This is not a cash grab: The tires you remove at the end of the fall will be preserved for reinstallation in the spring, and your two sets of tires will last twice as long. That said, there may be a cost for installation and storage, and probably an investment in a second set of steel rims for the winter. In Quebec, winter tires are compulsory from Dec. 1 to March 15, and in British Columbia, many interior highways require tires to have at least an M+S rating for winter use.
However, there are many different levels of quality found within tires that have the three-peak mountain snowflake symbol. The only qualification to be certified by the ISO is that the tire is able to accelerate 10 per cent better through mid-packed snow than a standard reference all-season tire. There is no test for braking or for lateral grip on ice.
“When the three-peak symbol came in, I thought, ‘Finally, we can have a tire with good ratings,’ until I figured out how they did the testing,” says Jeff McKague, the president of Event Matrix, which tests tires in real-world conditions for manufacturers and retailers. In his opinion, the symbol is intended more to prove a tire is legal in conditions that require it, such as winter in Quebec or on B.C.’s mountain roads, than prove it is capable of actually handling winter’s highly variable conditions.
Now there is a new rating for winter tires, as a complement to the existing ratings: the ice grip symbol (a triangle with an icy peak) is stamped on the sidewall of winter tires that can brake to a stop on ice at least 18-per-cent more efficiently than the standard reference tire. This is a very different requirement to just chewing through snow, and it now identifies those better-quality winter tires capable of such superior braking.
“The ‘ice grip’ is more of a real-world braking and traction test in icier conditions,” says Gordie Henderson, the director of passenger car and light truck retail products for Kal Tire. “The three-peak mountain snowflake [test] is done on medium to hard-packed snow, but doesn’t take it beyond that point. When you think of a snowstorm, if there’s any liquid in the snow, it’s going to pack, and when it packs it starts to freeze, and when it freezes, it turns to ice. That’s where the ice grip will make the difference.
“The three-peak mountain snowflake is more of a spin-traction test for acceleration, and the ice grip is more of a real-life, on-the-vehicle braking test.”
Aside from having specially designed tread and sipe (groove) patterns for sucking the tire to the ground and dispersing the ice and snow, winter tires are also made from a rubber compound that’s more pliable in colder weather. “As a rule of thumb, you should opt for a winter tire if it’s consistently below 7.2 degrees Celsius in your area,” says Jenny Paige, the director of consumer product planning for Goodyear Tire & Rubber Co.
“Many people don’t realize that all-weather and winter tires may be more appropriate in freezing temperatures, not just snow. The special rubber compounds in all-weather and winter tires are designed to help increase pliability at low temperatures to provide enhanced traction in more severe winter weather conditions including ice, slush, freezing rain and snow.”
In fact, non-winter tires do not become suddenly incapable below 7 degrees Celsius. The temperature is a direct conversion of 45 degrees Fahrenheit, which is a number easy to remember for American consumers. That is the temperature at which most summer tires, made from soft and sticky rubber for superior performance on sports cars, become too hard for safe use on asphalt. All-season tires can maintain safe pliability at colder temperatures but if you’re going to swap over your rubber, the rule of thumb of 7 degrees Celsius is sound advice.
All-weather tires are more capable in cold temperatures and for driving through snow and ice than all-season tires and do not need to be swapped over when the seasons change. They’re more durable on hot asphalt in the summer. They normally qualify for a three-peak mountain snowflake symbol but are not as capable in winter conditions as dedicated winter tires. However, they may suit many drivers who live in balmier areas of Canada, or who do not have to venture out in bad weather.
The new ice grip symbol was agreed upon by the ISO in 2021, but not all tires that deserve it will have the symbol stamped on their sidewalls. Kal Tire’s Henderson says many manufacturers do not want the expense of retrofitting their machinery to include the stamp until the next generation of the tire is ready. Until then, it’s best to look at the test results and ask your tire dealer for a recommendation.
“Tire makers focus on three aspects when designing tires: tire wear (longevity), rolling resistance (fuel efficiency) and traction,” says Michal Majernik, the head of communications for the Tire and Rubber Association of Canada. “Each aspect of this performance triangle affects the other two, meaning that, for example, if the tire is meant to provide extra traction, the other two performance aspects will be affected negatively. Tire makers aim to expand this performance triangle evenly.
“Just as with any product, there are tradeoffs. So, the tires that pass this [traction]? test may have a softer compound or may lack in other areas of performance. We recommend drivers discuss their winter driving habits and road conditions with a tire specialist to determine whether a tire with the ice grip symbol is right for them.”