As far as the Amperage vs CFM comment, There is some validity to the comment, However, a high amp fan motor with a poorly designed blade will draw the amperage but not move the air.
An efficiently designed fan and motor will move the air while drawing minimal amperage. The trick is to find a supplier that does not "FLUFF" their numbers. Again, I like Spal and Flexalite.
True about a poorly designed fan drawing excessive amperage.
The OEM fans all draw fairly high current because of their capacity. There's no free lunch. Hard work requires hard effort.
The Mercedes fan shown above is by far the most powerful I've dealt with and is a really nice fit on our factory radiators. It spikes over 60 amps on soft startup and pulls more than 50 amps at full speed. Lower speeds obviously pull less amperage.
Spal makes good stuff. I've used their fans. Flexalite is hit and miss. Their low priced fans are too weak for primary cooling.
