Your driving safety is the main reason why you should change to winter tires. This assumes that will drive in winter conditions that include snow or ice.
Winter tires outperform all-season tires once the temperature drops below 45° degrees. There is no need to wait for the snow to fall or ice for you to change to snow tires as they already perform better at low temperatures. On ice and snow, the winter tires are far superior to all-season tires, which will provide almost no grip in these conditions.
On snow, both the studded and non-studded tires will perform well. The choice is up to you and where you will drive. Non-studded tires have a bit more flexibility, as no regulations limit their use. This can be very useful if you plan to travel across state and province borders.
The studded tires are made for ice as the metal studs can create a better grip on ice. The non-studded tires will use the tread design combined with grip particles to create grip on ice.
Winter approved tires will have a symbol showing a 3-peak mountain with a snowflake inside it. This means that the tires have passed the stringent tests required for approval.
You should always change well in advance before the snow arrives. Since the winter tires are superior to all-season tires when the temperature drops below zero, you should use that as the moment you change tires.
For more information regarding winter tires, visit: https://www.nokiantires.com/