I would like to see some tests that support this statement. Apples to apples. In other words the electrical fans tested pulled the same volume of air that the clutch fan did.
Or another test would be to average the volume of air pulled and average the amount of HP required (over say 10 hours), since both thermo-clutch fan and electrical fans both do not pull consistent volumes of air.
If you move the same volume of air, how would there be less drag? You cannot do the same work and use less energy unless there is an efficiency increase right? An electrical fan scenario, you are turning the alternator which is like 70 - 80 % efficient, then running an electric motor that is similar in efficiency you have lost 40 % of your energy in the electrical process. Only if the electric fan blades were more efficient in ability would you gain some efficiency back. So, why not just put an equally efficient fan blade on the clutch and save 30 % of your used energy?
The only real way the electrical fan uses less energy is that they pull considerably less air, therefore using less rotational power at the alternator.
