Originally Posted by jamstoyz
i heard the electric fans are great and free up some horse power
Err.. On a gasoline engine. I don't think anyone that I know of uses an electric fan on a diesel. I don't expect the engine to last too long that way. Diesels get a lot hotter than a gas motor. And they weight like 3x the amount. It takes significant cooling to keep a diesel working. I don't think any electric fan is going to cut it.
Further more, it may take X amount of horsepower to move the air necessary to keep your truck cool at idle or low speed with a mechanical driven fan. It will still take X amount of power to keep your truck cool at idle or low speed with an electric fan too. There is no overall difference. The reason being is that you may drag your engine down with a mechanical fan while it's clutch is engaged. The rest of the time (hiway driving mostly) there is enough air flow to not need the clutch engaged. You will end up using the electric fan the same way, mostly at low or no speed situations. It will still take the same amount of work being done to cool the truck. It will just be electrical work being done instead of mechanical work. Further, that electrical power comes from.. (you guessed it) the alternator.. Which means that the alternator is going to be dragging your engine down instead of the fan. In the end, you don't get something for nothing. Actually, you get less than something for nothing with an electric fan. It is actually more efficient over all to belt-drive a fan than it is to belt drive an alternator, use that rotational force to create electricity, then convert that electricity back to rotational force. You see what I mean?
just my $0.02