When to change your winter tires
May 21, 2013 1 minute read
Canadian springs and falls are unpredictable - teasing us with summer-like temperatures one minute before dumping a fresh load of snow the next. With the changing conditions, when should you change your car’s tires?
A general rule to follow is once the average daily temperatures are over +7C, you should change those winter tires for summer or all-season versions.
Different types of tires are made with different rubber compounds, which allow them to be optimised for a different temperature range. If we use a tire outside of its comfort zone, its ineffective relative to other options. All-season tires begin to lose their grip once temperatures drop below +7C and are useless for any temperature below -10C. Summer tires turn as hard as hockey pucks in the winter, while winter tires start losing grip as temperatures climb.
Winter tires are designed with flexible treads for below-zero temperatures and have more treads to allow the tire to grip onto ice. In warmer temperatures, these features become counterproductive.
As the tire turns, the tread comes into contact with the hot pavement and the friction creates more heat. This causes the tread to open further, increasing the surface area of the tire making contact with the pavement, resulting in more heat. You could say it’s a vicious cycle. The tread wears down quickly, impacting your ability to brake and forcing you to replace the tires sooner.
In fact, recent CAA tests showed drivers had less control of their vehicles and took longer to safely stop when they were driving with winter tires in warmer months. Impairment began when drivers reached a speed of 50 km per hour, even in dry conditions. At speeds over 85 km/h, they had lost all control of their vehicle. In wet road conditions, it took even less speed for the drivers to feel the impact.
While we’re almost guaranteed to experience freak May-snowstorms, rest assured your all-season tires should be able to handle it for a day. Just give yourself extra time when driving, slow down, and increase your following distance. Whatever you do, don’t be tempted to keep your winter tires on year-round just to save money. You could be more at risk by driving with winter tires on hot pavement. In the long run, changing your tires to match the appropriate weather conditions could also reduce your chances of an accident.