Run electric fans all the time?
At worst, it's possible that running the fans at speed is at least partially obstructing the free flow of air. Although even in that "worst case" scenario you'd still be moving the amount of air the fans are rated for,
I don't agree that running fans are an obstruction. A fan that's stationary has more back pressure (to the air being forced through the grille) than one that is turning, since energy has to be expended to spin the fan and motor.
Not only that, the fan rating is at a specific back pressure on its output side (probably zero for pullers open to the engine compartment), and (AFAIK) assumes zero obstruction and atmospheric pressure on its inlet side. While driving at highway speed, the pressure of the ram air coming into the fan (after passing through the grille and radiator) is
above atmospheric so if the fan's running it should move more air than its nominal rating.
However. It
is true that there should be no need to run the fan at highway speeds. So why use a mechanical fan... which is turning all the time, even through a viscous fan clutch which consumes some power? :p
So either my t-stat is too restrictive (I just got a Milodon 16406 high-flow 180F to try) or my old copper-brass 26" rad isn't cutting it.
I started with a bare rolling shell, so I designed and built the entire wiring system from headlights to reverse lights. My 130 amp alt puts out 95 amps at idle. I can spare 40 amps to run the Contours when they're needed :) Not only that, the clearance to the core is so tight that even with the short Hayden fan clutch I don't feel comfortable running that big steel finger-remover.
