My first HHR came with all-season tires.

In the snow it was just barely OK.

I installed Bridgestone Blizzak snow tires for winter. The HHR was a totally different animal in the snow. Great grip, minimal sliding.

I now use Blizzaks during winter on all 5 of our HHR SSs (and on my 2 daughter's HHR LTs). Also used them on our minivan we had, and now getting them for our Suburban.

A warning: the really good snow tires will wear quickly during warm weather, so put them on just before the snow starts, and then remove them as soon as the weather starts getting warm (April or so).

Steve

 

Our 2 new LSs came with Firestone all-season. Poor grip in all conditions, noisy, wouldn’t stay balanced, shaky, pulled, poor life. Other than that they were fine. Maybe poor life was the best feature, allowing replacement with Pirelli P4’s that seem to last forever and are better in the snow. (Our terrain is mostly flat and we rarely get much snow, so we don’t worry about the perfect Winter tires.)

 

My Hippo also came to me on all-season Firestones. I could hardly believe my eyes, all-season tires shouldn't be like that, I thought then. Indeed, they barely gripped even the cold asphalt. Ice and snow are not for these tires at all. Later I used them only in the summer (well, I can't throw them away!).
It just so happened... Now my Hippo is wearing Bridgestone Blizzaks. True, not Japanese but Russian-made, but still very good.

 

I switch to winter tires when the temperature is below 7 C or 45 F in the fall

 

I have set the following algorithm for myself:
1. from summer to winter tires - October 15;
2. from winter to summer tires - April 15.
Regardless of the weather.
Such recommendations are given by the Ministry of Transport to transport companies for our region of the country. I have never regretted my decision, especially convenient if the winter tires are not studded.
I have two sets of wheel rims for both cars - this is convenient in the sense that you do not need to stand in line at the tire repair shop. When the whole city realized that tomorrow it will get colder and a huge herd decided to change tires at the same time lining up in a giant queue, I just take a jack and a wheel wrench and change the wheels. Free and hassle-free.