Cross-marketing?.

Winter grade tires suitable for deep snow must have deep, coarse lugs. The rubber should be stiff rather than soft.

Winter grade tires suitable for salty slush should have grooves radiating away from the center line to channel the slush outward. This allows maximum contact between rubber and road at highway speeds.

Tires suitable for ice pellets over a few inches deep would probably work best if they were deep-lugged, no particular rubber preference.

Tires suitable for black ice...Oh, wait. There are no winter-grade tires suitable for black ice.

Back during the '50s one of the tire manufacturers did come out with tires that worked well on glare ice. Only problem was, they were useless in deep snow, ice pellets or slush.

If I recall correctly, they consisted of finely sliced, very soft rubber arranged in tightly-spaced radial hoops, something like spiral-sliced hams, only with very thin slices. Apparently, these treads were meant to spread and deform for maximum adhesion, something like the underpads on a gecko's feet.

They worked, but were useless for any other road conditions and deteriorated very quickly. Even though black ice is by far the most dangerous of winter road conditions, they did not go into production.

One other stab at producing tires suitable for ice appeared in the late '60s. It consisted of winter-grade lugs with carbide  cleats inserted in the treads. That worked, but too many windshields were destroyed by flying cleats dislodged through wear and highway speeds. Also, there was unacceptable road surface wear. Complaints from road maintenance authorities put a stop to that.

It should be obvious that those winter-grade tires the Ontario insurance companies have been maneuvered into promoting are designed to sell everyone an extra, and unnecessary set of tires and maybe wheels, too.

There is no such thing as tires suitable for all winter weather conditions. The closest thing is all-weather formulas, which the tire people have been selling to responsible motorists for over 50 years. The earliest versions that actually worked well were the Custom Suburbanites. I forget if they came from Good Year or Firestone.

The insurance involvement is the equivalent of a marketing scam designed to scare people into buying another set of tires. And after that, also storage space for that extra set of wheels for people with no extra storage space.

And what's in it for the insurance companies? Well, an easy excuse to jack up customers' premium rates at the slightest provocation, of course.

Apparently some savvy marketer figured this would be an easy sell to the Ontario electorate. It's possible they consulted with the politicians on that one.