Is it established for winter tires and wheels to be narrower to accommodate slush build-up?

Question

On fat bicycles — those with 4" tires, meant for riding on snow — you'll occasionally hear someone saying that 5" tires will fit with no difficulty in a given frame. Yet I'm inclined to continue using the OEM 4" size as that gives me more space for slush build-up during winter rides, on roads and off-road, delaying that the wheels will start to scrub against the accumulated slush.

Now I'm wondering whether a similar phenomenon is better studied, or perhaps even well-understood, for winter car tires and wheels (rims).

On manufacturers websites, the option for winter tires are 10mm-30mm narrower than summer tires, and (as a consequence) the option for winter wheels (rims) are 1" to 1.5" narrower.

Is it established for winter tires and wheels to be narrower to accommodate slush build-up in wheel wells?

Again comparing with bicycles, a narrower tire makes it easier to ride over snow, since that is the width that I need to compact — in essence continuously "climbing over" small hills that I then flatten. In a car on the roads I'm seldom the one who's compacting the snow (the first or the heaviest), and so I doubt that justifies the narrower tires. Can you confirm?

Just to complete the comparison, note that switching from 4" to 5" tires on a bicycle requires a (simple) cyclometer adjustment to continue obtaining accurate speed and distance readings. This would be more complicated in a car. That is why we can talk about using narrower wheels, but the diameter must remain close to that of summer tires.

Answer 1

In a slightly different vein from Weather Vane's comment --

Slush buildup may be a problem for bikes, but it is a non-issue for motor vehicles. Wide tires tend to float on snow. Narrow tires, as Weather Vane points out, exert more force per unit area and therefore they tend to dig in to snow and get all the way down to the pavement, where the real traction is, instead of floating.

Ever notice the extremely thin tires on old Model T Fords? Roads were mostly unpaved during the early years of the 20th century, and Model Ts were legendary for getting through snow and mud because their skinny tires dug through surface snow and muck and dug in to terra firma, quite literally.

Answer 2

Again comparing with bicycles, a narrower tire makes it easier to ride over snow, since that is the width that I need to compact

I tend to disagree.

Try to ride on partially melted and then again frozen slushy snow on 35mm wide bicycle tires. You see what I mean. The bike is all over the place, the wheels don't go straight. The slushy snow will literally attempt to kill you. Staying upright in those conditions is very hard.

Then pick a fatbike. According to https://bicycles.stackexchange.com/questions/92429/is-a-fatbike-easy-to-keep-upright-in-uneven-melting-slush a fatbike can handle those conditions just fine.

Bike tires need to be wide and have a low pressure to be able to be used on slushy snow. Narrow tires aren't easy.

On a car, the situation is somewhat different. A car can perfectly well go in a non-straight curvy path in slushy snow and still you as a driver won't feel like the slushy snow is attempting to kill you. A car will always keep upright. A bike won't.