How anal do we want to get? A mech fan with 6 blades and steep blade pitch is gonna suck some HP down. The losses with a mech fan should be quantified thus:
Windage losses, inertial loss, frictional loss in pump bearings and belt(s). And if you're not using a flex or thermostatic fan, the losses increase as RPM increases mostly due to increased windage thru blades.
The electric fan's electrical load doesn't change once the fan is running steady-state. Its RPM and load are independent (mostly) of engine RPM. 14 amps at 14 volts is 196 watts. Since 746 watts equals one horsepower, 196/746 equals .2627 HP, roughly 1/4 HP. Does a mechanical fan draw more or less than 1/4 HP at 3000 engine RPM?
