Originally Posted by michaelingp
The studies I found involve twin engine planes when one engine quits. The pilot wants to continue flying on one engine, which means the dead engine's prop is going to want to turn almost the same speed as the engine that's running. To do that requires a LOT of power, hence a lot of drag.
Right, but you're talking about a completely different motor, not a brushless. Even if you scaled down in size, the force required to spin a prop on one of those engines, due to friction, is a lot more than one of ours needs. That's the only reason it requires a lot of power in that scenario.
So not only does it make less difference at low speeds, but also at low internal friction in the motor.