This was my first time in heavy snow with the HHR. Grade report: A.
I got rid of the 17" Firestones some time ago. Replaced with Cooper CS4's for spring/summer.
For winter, went down to 15" steel wheels, with Continental Extreme Winter, 215x65x15. They were truly amazing! Deep virgin snow, slush, ice, braking, slush/snow combos, inclines, curves.........very impressive!!!!
I know I went with a slightly narrower tire than recommended. I was interested in the snow performance vs ride quality. Tire Rack and the dealership checked and gave me the thumbs up.
Took on the CT storm yesterday. This weekend it will be Maine.
Two thumbs up for the Continental Extreme Winter tires.

 

Are those Continentals studded?

 

No studs. I spend a lot of time commuting between CT and ME. These tires are very quiet at speeds of 65-75.