“My all season tires are good enough,” is a sentence often heard during Calgary winters as we battle through the snowy weather to get where we’re going. However, anyone who has experienced the benefits of winter tires knows this to be untrue. All season tires, despite the name, are not good enough for all seasons. Not Calgarian seasons anyway.
This is where the confusion arises. ‘All season tires’ should come with an asterisk that their seasonal flexibility is for wet and dry seasons, not for hot and cold. The defining feature of an all season tire is the treads, which are designed to prevent hydroplaning on wet roads. Hyrdoplaning occurs when the tire can’t move water through its treads at a high enough volume to maintain contact with the road, causing the driver to lose control of the vehicle. All season tires prevent this by designing the treads to move water through them more efficiently and maintain better control on wet roads. How does this tread design help in cold temperatures? It doesn’t, at all.
The problem with tires in cold weather is that the rubber begins to harden below 7°C. Once the temperature drops to -10°C, the all season tire material becomes more like a hard plastic than a flexible rubber. When a vehicle hits a patch of ice in temperatures below -10°C, those all season tires are not going to have any traction. The vehicle might as well have summer tires. Even when it comes to driving on snow, the treads in all season tires are too thin to maintain traction effectively. Tires designed for wet weather are simply not good enough for cold weather.
Winter tires, on the other hand, are made with a rubber material designed to be more resistant to cold temperatures. When the temperature falls well below zero, they maintain their rubbery flexibility and will not lose nearly as much traction on snow or ice. The distance required to stop the vehicle is reduced dramatically. When you’re coming towards a busy intersection and need to know accurate braking distance, do you want hardened tires with limited traction? Probably not. This is the situation that all seasons will put you in, and that winter tires prevent.
The material used in winter tires is the most important feature, but its tread design is useful as well. All season tires have thinner threads incapable of taking on thick snow. Winter tire treads are specifically designed to take on snow and further increase the surface area of the tire’s contact with the snow – increased surface area means more friction, which means better traction. More advanced winter tires even come with small metal studs, providing more grip and preventing the vehicle from sliding when accelerating.
The province of Quebec has already made winter tires mandatory between December 15 and March 15. Alberta and British Columbia have them as a requirement to drive in more mountainous areas. Other provinces are looking at introducing similar legislation, for a very good reason. Only winter tires are appropriate for Canadian winters – all seasons don’t cut it.