So I've installed the dual 15 inch fan kit by flex-a-lite and my mileage has gone down to approx.220 miles to the tank from approx.320 before the install. My edge evolution tells me the loss is occuring while doing city driving. The instant miles per gallon gauge tells me I'm getting approx. 8-9 miles per gallon as oppose to my regular 12-15. I've gone through 3 tanks since the install and on these last two I've been really easy on the gas pedal but to no positive result.The fuel filter is 8 months old and my oil change and air filter cleaning is almost due but not late.To add to this my engine bogs out and dies when I start it while giving it gas.Don't know how bad this is.It's a habit I got into because I liked to hear her roar when I started her.Any and all help will be greatly appreciated.

 

Do you have a programmer?

 

well i wouldn't get into a habit of giving it gas right after start up. It scars the pistons wall because there is no oil up to your pistons yet.
I dont know how you could've decreased your mpg by just putting electric fans on it.

 

there is definantly something wrong, like I suggested on a couple other forums, change the o2 sensors, clean the MAF check for a vacuum leak and have your cats tested

 

Load your stock tune back and run it like that to see if it makes a difference...

 

Could the fans keep the engine too cool and cause poor fuel economy?

 

It shouldn't if you "tuned" the fans to come on at the proper temp. In fact, at start up, the engine should warm up faster.

 

Well I checked the tire pressure-ok, checked the intake air tempature using my edge evo-nothing out of the ordinary, popped the hood and checked out my hoses around the air intake and I couldnt find anything that looked funny. The Fans are tuned properly to the coolest setting (counterclockwise) and turn on at 60% when my vehicle hits 188 degrees and really get movin at 100% when the vehicle hits 195.Before the install my temps would fluctuate between 186 and 192 degrees F.I've explained every detail I've covered so far and I'm still stumped. Gas tank approaching E at 240 miles in when I'm regularly 320.Called Flex-a-lite and they were useless. They tried to pass it off on my KN Gen 2 Intake saying that because of the increased airflow that was being pulled through my radiator that the intake was recieving more hot air than it should to run effeciently. Sounded logical till I started monitoring the intake air temp and thats normal!So I guess I'm looking for a plan of attack to see what I should tear out and clean or replace.Any Ideas?

 

I still think you should try this!

Load your stock tune back and run it like that to see if it makes a difference...

 

Will do PZX 2002. Thanks for the advice and I'll reply in a few with the outcome on the mileage.

 

When I installed my troyer fans I had the same problem just not as drastic. Did you use a actual temp gun to know when to have the fans turn on? Or are you using the edge? It will take at least 15 mins or so to get to 190 degrees F in 110 degree heat. I messed with the fans coming on for a week. And after I messed with it I kept uping the degrees in when they should come on. Since than my mileage has gone up. First fan comes on at 190 ish second one 200ish. Yes you need to actual get a temp of the radiator with a temp gun and not of the edge.

 

You have one fan right? 188 is too low and 195 is on the low side. Get the 60% to turn on at 194 and the 100% on at 204.

 

Well Desert racer,I messed with it for about a half hour and I'm getting the fans to come on at 60% at 196.On my flex-a-lite dual 15's my controller has a set screw dial that you manually adjust. So by messing with the dial and keeping an eye on the edge temp gauges is how I know the temps that they were turning on.Before the fan install the trucks temps stayed within 188 to 196.So that I understand, could you please explain how the hotter running temps would ease this situation. I understood it as, a cooler running engine would be more efficient. I dunno. I'm on my 5th tank since the install right now. I'm approaching half tank with 105 miles on the odometer. I have to do some driving tomorrow so I'll have some more results,hopefully positive ones.Thanks everybody for the help and sharing of knowledge.

 

wow, you are getting some horrible mileage.

a colder engine will produce more power but get less fuel economy.

a heat engine (physics name for these types of things) is more efficient when you have the highest gap you can get between the hot resevoir (engine) and the cold resevoir (air). in this situation you can't really do anything about the air temp so you want to make the engine run hotter to widen the gap. the more the difference in temperature, the more efficient the engine.

 

DO NOT USE THE EDGE TEMP SENSOR. Get a handheld thermometer to see how hot the coolant is inside the radiator. I used the edge too and yet well crappy milage what you are getting. You need the motor to get to normal operating temp so it will combust and perform how it should. You are running the motor too cold and well performance is good fuel mileage sucks. And vice versa if you get it oo hot. So try it again with a thermometer and do not use the edge. As after 5 mins the edge will say it is in the 196 range. Yet the coolant is probably in the 140.