I highly doubt it can achieve anything close to 12000rpm. That's 200 revolutions a second. Electric motors only those rotary tools, dentist drill and high end blenders reach that kinda speeds. All those have small, metal blades/tips. Your fan blade so long and made of plastic, sure will shatter. Also, the motor required to drive such a thing would be huge, cannot fit between your engine and radiator.

At this speed it will produce alot of sound at a high pitch. Quite scary.

This post has been edited by djtong: Dec 21 2016, 09:59 PM

Correct, two measures for fans are CFM (volume of air moved) and static pressure (how strong it can pull air through the radiator). A fan with high cfm in the air might not have high cfm behind your radiator. RPM just tells you how fast the fan spins, without anymore info it's impossible to tell if it's a good fan or not.

Car companies spend millions daily to research cooling efficiency, if there is a better solution, it's them who'll introduce it, not some small fan company. Your high cfm fan at low speed can even restrict flow through the radiators at high speed.