The softer rubber and deeper treads on winter tires bite into snow more aggressively and increase traction. However the heavier tread and softer rubber also increase friction on bare pavement and therefore they can increase gas consumption as well.
Winter tires can be noisy and will wear more quickly, especially on dry pavement. The other disadvantage of winter tires is the additional cost and the necessity to store them during the summer. Vehicles that have low profile tires should consider switching to higher profile winter tires as low profile tires are much less effective than standard all season tires in winter.
More Winter Driving Tips.