As you're shopping for winter wheels and tires, you'll likely come across the recommendation of going to a narrower tire. This is the exact opposite approach that you would take for summer traction, where wider is better. If you're likely to drive through deep snow this year, you'll want winter / snow tires and wheels in sizes that help put the laws of physics on your side.
The reason for this is that traction is achieved in winter by cutting through the ice and snow. With wider tread, you're more likely to start snow plowing or floating on top of the surface instead of pushing down and through. This floating will result in loss of traction sooner than with a thinner or narrower option. A good way to picture this is imagine a pizza cutter slicing through a pizza.
Another way to think about this is from the perspective of the contact patch. A tire's contact patch or "footprint" greatly influences its performance and is dependent on its profile. The narrower the width, the smaller the contact patch will be. This is the area that makes contact with the ground as rotation occurs. With the vehicle still weighing the same, a smaller contact patch results in more pounds per square inch. This will produce more force on the tire to help it cut into ice and snow and deliver optimum traction for the worst winter will throw at you.
