jrichker said:
The electric fan pulls about 1/2 HP of electrical power. Using 746 watts = 1 HP, then 14 volts x 30 amps = 430 watts /746 = .56 HP.
The stock fan pulls 5-12 HP depending on who you ask. Any way you cut it , the electric fan frees up some HP, and can possibly increase gas mileage.
I've read similar info.
I noticed 1-1/2 to 2 mpg overall increase, mixed driving.
Fan doesn't run at all on the highway, or really as long as
I'm moving even 20 mph.
Taurus fan (4.2 motor 2 speed version)
Flex A Lite variable speed soft start controller
Had it on my 351 for a year, works absolutely great, no cooling
probl's at all, even in 90's weather, stopped at lights, idling in gear.
I've got an LED wired in the dash to tell me when the fan's running,
and at stop lites it'll come on for a very brief time and shut back off.
I've got a 3 core brass radiator, hi-flow 180 T stat, and a Weiand
hp pump, so the whole system has good cooling capacity.
It delays starting the fan for a few seconds when you turn the key
to start the engine, that way it doesn't draw to start the fan at the
same time you're using the starter.
You can also easily hook up switches for manual on or off.
When it does start, it runs at like 60% until/if the coolant
temp continues to get hotter, then it automatically speeds
up the fan as needed, all the way up to 100% if necessary.
I've got my control set for about 185. As soon as it kicks on, the
temp starts to decrease.
With the FAL control no relays needed, I believe it's a little cheaper
than a DC setup. $100 on Summit, you need the bigger of the 2
on there for a 4.2 Taurus fan. Real easy to wire.
http://www.flex-a-lite.com/auto/html/vsc.html
And I got SUPERB customer service w/questions etc from FAL.