If I have All Season tires do I really need to change tires when seasons change?  In one word: absolutely.
The outdoor temperature dictates when to change your tires. Here’s why.

Tires are made from a mix of synthetic and natural rubber, fabric, wire, and chemical compounds. All-season tire rubber naturally hardens when temperatures go below 7°C reducing traction. So it’s not only about precipitation such as slush or snow. Temperature alone causes all-season tires to lose the traction you need to control your vehicle in cold weather.

Winter tires, on the other hand, are designed with rubber compounds that stay soft in freezing temperatures. This allows you to turn, stop, and accelerate efficiently when the weather gets cold. So why not use winter tires throughout the year? Because they are soft and pliable, winter tire stopping distances are longer on hot pavement, and warm weather in general causes them to wear down quickly.

Driving without a tire change: is it noticeable?
Very noticeable.
On cold pavement, stopping distance for a car with winter tires can be 30 to 40 percent shorter compared to one using all-seasons. Conversely, on a dry road with normal temperatures, Consumer Reports found that a vehicle with winter tires travelling at 96.5 km/h requires 24 more feet on average to stop (when compared to one using all-season tires).

Change your tires twice a year.
Swap from all-seasons to winters, and vice versa, two times a year. Keeping the magic number seven in mind is a good rule to follow. Change to winter tires as temperatures dip below 7°C and swap back to all-seasons when things warm up above 7°C in the spring.

A new category of tire has emerged in the past few years: the all-weather tire. They are not the same as all-seasons, because—you guessed it—the rubber compound used for all-weather tires stay soft even as temperatures plunge past 7°C. What’s more, this new breed of tire also stops rubber from getting too soft when during the hot summer months.

Transport Canada’s made it easy for consumers to identify all-weather tires by requiring manufacturers to use a pictograph of mountain peaks containing snowflakes on the sidewall of tires that are truly suitable for all four seasons. If you don’t like change, you might want to try all-weather tires on for size!