Vanco, all what you just said sounds correct (based on years of experience in the automotive industry). I have yet to see an electric fan able to move more air than a fully engaged clutch fan @ high engine RPM's (would draw too many amps and rob too much power). Efficiency can be dialed in though and the big advantage is they can run @ full output while engine is at rest. It will be interesting to hear how it does in the summer, please keep us in the loop. Tim