Not all snow is the same, it depends on how well your local crewed salt/plow/sand surfaces, how much traffic, water content of the snow, etc. I grew up in the northwest which means when it snows it's REALLY wet, and there's not enough gear to clear it. Wet packed snow can easily be slicker than ice.
I don’t understand. How were you ever able to drive with snow at 3-5 inches without working wipers?
I've had that happen, where an ice ball starts forming around one or both wipers, raising it off the windshield. Lots of use of anti-freeze washer fluid helps, but whether or not you can see depends on how hard the snow is coming down and how well your defrost is keeping the windshield from fogging. You might find yourself with your head on your dashboard, peering through the 6" hole of visibility that remains.
I've never had snow tires and the last time I went off the road due to snow was 25 years ago. Granted, snow tires make travel better in winter, but are by no means a replacement for careful driving.
I have a P3D+ and still have the Michelin PS4S's on there. I know I shouldn't have but I drove in a snow storm last week, it was about 6" of snow and 25F.
YIKES. PS4S???? I've only tried to drive in the snow on summer tires a couple of times (PS2s, S03s), and unless the surface was billiard table flat, you are going for a very extended slide. They must have made huge improvements in summer tires over the past decade or so, if you're able to negotiate anything remotely close to being described as a hill.
All-seasons are fine-ish, depending on the tire, depending on the terrain.
I live in San Diego, CA so keep the same tires year round. It may be cold temp for most of the country and still be in the 70's here. It may get down into the 50's at night during the colder days in the winter, but back up to 60's or 70's in the day, depending on cloud cover.
That being said, I learned in the past that the tire rubber compound in the "Winter" tire is different than the "Summer" or "All Season" tires. For that reason, if I lived further north or high altitude where it was consistently below 50*f during the winter and had below freezing temps at night, I would NOT go without two sets of tires for each of my vehicles.
The "Winter" tire is not about snow, but about the temperature of the rubber on the tire. A good rule of thumb is to keep a second set of tires for winter, mounted on a heavy duty steel rim. When the forecast is for your first snowstorm to arrive in a few days it is time to swap out the tires. Then when the temps of spring have arrived it is time to swap back to the "Summer" tires.
I really do not understand why ANYONE living in the cold north would endanger themselves, their families, or other drivers, by NOT having two sets of tires for their vehicles. You are not saving yourself any money by having only one set of tires and you are putting yourself and others at risk. The only drawback is that you need to store the extra set of tires and then swap them out twice each year. If you live without a garage with space to store them, then find a tire shop or garage that does that for people, as well as doing the labor of swapping the tires. They do it for a tire rotation.
jmho
I don't disagree with your conclusion, but you've got your numbers way off. I have driven on rock-hard summer tires that just bounce and spin around freezing, but seriously, winter tires for "below 50f?" Obviously it depends on which tires you're talking about, but I ran Xice3 all California-winter on my Golf, and I've not found a single condition (down to say 25f) where I'd rather be on those particular snows than on Michelin PSS. Perhaps if you're comparing a very perfomance-oriented snow or all-season to the most cold-sensitive summer tire known to man you''ve got a point, but real snow tires are like driving on Jell-O in the dry.
Here's a good comparison that validates my impressions, and, at least for the braking test, I'm seeing 26F as the operating temp.