[Piwoslaw]

I have an efficient engine. So efficient that it doesn't produce too much waste heat most of the time. My hypermiling techniques further increase the efficiency to the point that during the colder part of the year I need to fully block both of my grille openings and add thermal insulation, and the engine still barely gets up to temp.
Would this waterless coolant reduce my fan usage?

Even if I had a less efficient engine (like a gasser, maybe?) and didn't hypermile, I couldn't just pour the stuff in and be happy. I'd have to rewire/reprogram the fan and its electronics to turn on at a higher temperature. And maybe replace the thermostat, too. Then the engine would be kept at a higher temp, maybe increasing efficiency, but more likely increasing knocking. So the timing should be changed. Oh, and then the seals and other elements in the engine and cooling system may not have been made to withstand higher temperatures for longer durations, so they might fail sooner.
OK, I might be exaggerating, but those are some of the problems I can think of.

What I'm getting at is that just replacing your coolant with a waterless version most likely won't reduce your fuel consumption by 10% just like that. The changes need to be a little deeper.