Electric fan install help.
Main electric cooling fans came into being ONLY because of front-wheel drive technology. With the engine mounted laterally, with the crankshaft and typically all the major accessory shafts parallel to the front axle, so as to directly drive the transaxle, a fan, mechanically mounted on an accessory pulley would blow sideways and would not face the radiator. This is why electric engine cooling fans had to be and are used virtually universally in front-wheel drive vehicles. Modern engines are designed and intended to run at much higher temperatures than in the past and the electric fan provides adequate cooling to that scale. The conversion of mechanical energy to electricity and back to mechanical rotary power with a fan motor is less efficient in a number of ways than a direct mechanical connection. Mechanical fans are still common in trucks, SUVs and some RWD cars presumably as a result of sound engineering judgement.
Other than it being a requirement in FWD cars, and partially on the higher temps, you're totally wrong.
Please show me a new RWD car with a mechanical fan. You won't find one. Not the hellcat, not any LX body car, not the camaro, not the vette, not the cts not the mustang, not mercedes, not bmw, not Hyundai Genesis. There aren't any. For pickups, I know the 3.6 Rams have electric fans and I also believe that the ECODiesels have electric fans as well. Mechanical fans are getting far more rare on GM trucks as well, and I doubt they exist on any V6 2011+ F150s, as I haven't seen one personally. You see mechanical fans on 3/4 ton + trucks because they don't care about CAFE standards there. At that point it's probably a cost saving measure more than anything anymore.
Why is this? Because electric fans are more energy efficient. And they work. They can actually be turned off. This saves fuel. The auto industry HAS to be obsessed with saving fuel thanks to the CAFE standards. They can run at a higher temperature because they have better control of the temperatures as well.
I've written this ad nauseam but the only thing that governs the electric fans horsepower draw is ohm's law and the alternator efficiency.
Ohm's law= Power=Current*Voltage. So, pretty much every electric fan is going to draw under 50A steady state current, and let's say you're keeping the battery topped off at 14.6V. So, 50A*14.6V=730W. Alternator efficiency is let's say 55% which is probably even a little ineffcient. So, 730W/.55= 1327.27W. 745.7W in a HP. So 1327.27/745.7=1.78hp. That's the most the electric fan could EVER draw. Now, most of the time you care about power, it's off. It's on at idle where you'd have plenty of headroom. It's likely to really only draw 20A for the fan as it is, so less than 1 hp load at the constant speed it's running.
Your engine doesn't have to accelerate a mechanical fan which is basically a weight with a large lever arm. This is helped somewhat by a clutch fan, however you still have losses with the fluid coupling. It cannot be turned off.
Here's a commonly referenced car craft article
http://www.network54.com/Forum/215655/message/1066184641/Car+Craft+Cooling+Fan+Dyno+Test
My electric fan on my Duster is on for about 20% of running time. Overall it's using less energy. Unless the A/C is on the stock FWD car I have barely has the fan on at any time when it's not idling or running below 15 mph.
Sound engineering judgement is to use the most overall energy efficient fan that can keep the vehicle cool in the test environment. The car companies do heat tests in death valley in the summer.