I know how big a 5 horsepower 110/220vac single phase electric motor is, and also how flipping heavy it is.
I gotta wonder about a 12 volt DC one. Remind me again how many hp the oem Mopar 1970 electric starter was rated at. Wasn't it 1.8hp? and wasn't it about as heavy as a cylinder head,lol.Well I guess the actual motor part was only half a head's-worth. And it only turned about 400rpm under load, but it spins up up pretty good without. I wonder how big a fan that thing could power up? Hmmmmmmm
Lessee where can I fit that monster in. Oh I know; off to the side with a belt.... wait ......what? I think that's been done before,lol.
The question was posed, does the fan care what drives it? Answer is no. Now go hook that fractional hp electric motor to an all steel,hi-attack,7 blade fan, and take your car for a rip around town, and see if it can keep up,if it can even turn it,lol.
The electric fan works when there is enough time between hi-outputs for the rad to absorb the heat, and enough time for the mini motor to catch up. It works in drag-racing because the cooling system sees 12 or 13 seconds of massive heat going into a cold system,during which time ram air is doing most of the work, then has maybe 20/30 minutes between rounds to get rid of the heat. No problem right; it's just a time delay device.
But in traffic, this is a continuous input of heat, so it takes a continuous effort from the fan, and if she ain't up to it, well,then maybe you lose an engine when detonation sets in. Or you pull over and twiddle your thumbs for 20/30 minutes,circumstances permitting.
I'm not willing to suffer that kind of nonsense.
And there is just no good reason for performance street car to not have a mechanical belt-driven fan. Nor for a 430 or less hp car like mine, to have a monster rad in it. ( I have no experience with more hp). As soon as you have a proper functioning cooling system, any old rad that passes air, passes water, and still has the fins attached; will do.
And that's AJs opinion.