All-season tires are designed for a variety of road conditions like dry roads, wet roads, and light snow. Winter tires on the other hand are designed to perform best in winter temperatures and conditions like ice, slush and snow. The rubber compounds in the tread of winter tires are designed to stay in contact with the road surface especially in temperatures below 45 degrees whereas the rubber compounds in All-Season tires harden as the temperatures decrease causing reduced traction. This gives winter tires improved grip and braking characteristics when you need it most this winter. Even on a vehicle with all-wheel or four-wheel drive, winter tires are important. An AWD or 4WD system can help a vehicle accelerate, but will not improve braking characteristics. Don't loathe winter driving, love it by preparing for it now!