Tire Size help...

Mergnthwirker

Fat tires will "float" on the surface, especially in deep snow. Narrower tires give better traction in loose snow. Ideally you might run 225's all around on 18" wheels, if you could find a set that would fit. I think 235/40-18's might work on the base Z wheels?

The other key issues are tread design and rubber composition.

For tread design, there are two issues: ice performance and snow performance. For ice performance, you want lots of little "edges" in the tread to help provide traction. Micro-siping of winter tires and multi-cell treads are attempts to provide this. Or you could just go for studs! For snow performance, snow grips better on snow than rubber does, so modern snow tires are designed to pack in and hold a bit of snow in the tread. Older designs (mud tires) try to have open patterns that throw the mud and snow out and keep the tread clear.

Most non-winter tires get hard when it gets below about 40 degrees F. They provide very little traction even on dry roads in the winter (in the northern climates).

I tried a bit of ice-racing once. A bunch of guys there used to gin up their own tread batches, including embedding walnut shells in the tread which created lots of pockets for better grip. And in the studded classes, they had incredible stud arrays that might be classified as deadly weapons. They would throw up huge rooster-tails of frozen snow/ice as they buzzed around the lake. Fun stuff!