Well that just plain doesn't make sense, haha. I can't see what is causing your mileage to suffer here, personally.

 

Get the $20 kit from Autozone, you can dial in a potentiometer to the EXACT temp you want the fan to go on.

As for the other guys post, I call bs on the fan not giving you more power and mpg. People probably don't notice it because they're on the throttle more. It may not be huge increases but it definitely helps. Turbo engines not being beaten deliver the best gas mileage but most never see that because they're into the pedal, I think the same thing is going on here. At the time you're comparing the power you're also trying to compare gas mileage which will fudge your results & opinion of what the mod did and any opinion weeks afterward was not even documented because the first week already made up your mind it was not detectable. This is like a musician, just because some people cannot hear certain octaves does not mean they do not exist or infact help the overall composition of music, other people more in tune with their vehicle will certainly notice a difference in installing an electric fan.

Hot Rodder math generally states that throwing an electric fan on your engine frees up about 10-15hp....maybe more if your mechanical fan was defective and not disengaging ever (yes Hot Rodder Math lol still prefer a dyno but the estimates are fair). That fan weighs a lot and is a lot of drag especially when its doing its job, crap just installing an aluminum crank pully that weighs a few pounds less can increase engine power by 4-5hp let alone removing a mechanical fan.

 

That's actually an accurate statement. My dad was an automotive engineer and once explained all that to me.

 

i know strange eh? i think it might have had something to do with the stock fan acting like a propeller and pulling my truck along.
i didn't say there was no power difference. i just said i got worse gas mileage with the electric fan than i have with the mechanical fan. now i do think i noticed a bit of a power difference but that could have been me messing with the tuning.

 

I felt a difference in power, but as stated, several other mods done at same time. I was getting just over 10 mpg and now get just over 13. But it was a comnination of things. No way to isolate.

And the controller has three settings which are variations of fan on temp (one fan and only 50%, all the way to both fans at 100%, and temp to start slowing them down based on temp.

I got the TCP kit. I know, a lot more expensive - but it LOOKS sharp too! Sometimes, you just gotta fly first class!

 

I'm with "gdstock" on the looks and quality of the TCP fans, not sorry I spent the extra $$ plus it all came in a kit so no searching around for parts. I also put on a modded kegger, timing chain and a modded throttle body when I put the fans on but damn sure noticed a power increase and a 120,000 mile motor that just sounds great. Pulling a 5,500 lb. payload @ 55-60 mph gets me 11-12 mpg, running no load @65-70 in overdrive nets me 14 mpg so I am happy with the electric fans and would do it again.

 

I see what you're saying, but the worse gas mileage doesn't completely make a whole lot of sense, thats the part I was calling bs on. If you have more power due to less drag, thats also less strain that would hurt your mileage but at the same time like I said before, you're probably into the throttle a little more and not even realizing it because of the feel of a more robust response. It would be the same as saying you took 500 lbs of weight out of your truck bed and got worse mileage with a lighter truck. If you're getting worse mileage its not because of your electric fan. Even if you're going to factor in the only other resonable explaination of more alternator drag it would also cancel out the power gains you said you definitely felt. Alternator drag due to more electricity needs is not even a factor when comparing it against a mechanical fans stress on the engine.

I can completely assure you that your electric fan is NOT hurting your mileage what so ever, especially since you said you have more power since putting it on. I'm not saying its going to give you a 1-2mpg increase but I am saying its NOT taking anything away from your fuel efficiency.

The $20 kit I mentioned does not include the fan, you supply your own fan its just the controller But its got complete adjustability!.

 

I have a question. I have a fan from a mark8 I got from the junk yard and I got a pusher fan I am going to put on the front for my A/C that will only be on when the A/C is on. I have a 195 t-stat in my truck. what temp should I set for the main fan to turn on?

 

i think it depends on how fast the fans are able to cool things down. with the dual electric fan setup i have on my truck i would probably set them up to kick on at 195-200*f area. then hopefully the fans would never come on unless they are really needed.

 

The TCP kit includes controller, which allows more flexibility and control. More elaborate than necessary, but works great. The kit also includes fan and a welded aluminum shroud complete with correct mounting for overflow and wiper reservoir. The only downside of the TCP kit s the cost is more than some can/want to pay.




I would set temp about 10 degrees over, so 205 degrees. If you set at 195, it will cause tstat to continually open and close and temp will always be "hunting." See how that works and then adjust from there.