best fan option out there?

Ok guys, there are two main types of fan clutch.
One uses a bi mental spring on the front to sense the air temp going by and adjust the hydraulic action (kind of like an adjustable torque converter) and the other is an internal heat sensitive valving system. (still may be bi metal activated but I don't know exactly how those are built.)

The one and only way to test one without driving it is that it has some resistance when you try to turn it by hand (some resistance, not much)
Now if you take that same clutch and twist it back and forth real fast a few times the resistance get less and less because it's cold and therefore is not needed for cooling so they start releasing.
This gives that power to the engine since the fan does not need to be driven at that point in the temps.

Now, when it senses hotter and hotter air flowing around it the valving system (bi metal or other) closes down the slip and drives the fan somewhat of an amount closer to engine RPM's but never a direct one to one, because the clutch always has some slip.
At this point is where you hear the fan kick it at higher RPM's.

A correctly working fan clutch will also a lot of times kick out at higher RPM's unless the engine is really getting hot so it does not take away from the top end power of the engine.

If you turn a sitting cold one it will have some fair resistance, but will turn fairly easy.
If you have one that does not turn at all then it's bearings are frozen up and it's bad.
If you ever run across one that just free spins when the car isn't running, it has lost it's oil or otherwise has a broken mechanism internally and is also bad.

There. :D

Didn't know anyone ever made one that ran 1 to 1 with the motor. Huh