Home with our young daughter today. Went out to run an errand. On the way out, going downhill, I passed a $50K Lexus that was trying to go uphill. It was half off the road. There's a trend in modern cars, especially luxury cars, for "performance" tires. Typically that means larger wheels and a higher aspect ratio (If your car has 225/60-15 tires, they're 225 mm wide, on 15" wheels, and 60 is the aspect ratio, a measure of the distance from the rim to the road compared to the overall diameter of the tire. If you see a car where there's a lot of wheel and the tire looks like a rubber band on the wheel, that is a low aspect ratio, high performance tire. Very good on summer roads. Bad in the winter. They ride up like a surfboard.
I'm not a tire expert, but that's what I hear and what I've read.
My car's like a snowmobile. I have an Audi A4 with all-wheel drive, and winter tires on it. When I bought it there was a performance package option with 17" wheels and special tires. It explicitly said you shouldn't run these tires in winter. I stuck with the 15" wheels and all-season tires. This year I decided it was time to go with winter tires, and there is a big difference.
I was just thinking when I passed the Lexus that they could have spent another $500 or so on winter tires, and not had that problem. If you're driving a car that expensive, you can afford the snows.
If things go well, maybe this spring I'll buy 17" wheels and summer tires, but I'm keeping the 15s for the winter. :-)