When i bought my 04 FX4 last fall i was getting 18-19mpg and not im lucky to hit 16mpg wtf???? I have had the tranny rebuilt rear end reabuilt, cam phasers replaced, fuel filter changed every 15k and oil every 3-3500... Any Ideas>>???? 2004 FX4 believe 3.73 gears. super cab short.

 

16??? I have the exact same truck as you and I have never got over 15. I guess it is what it is. Thats why I also have a escort that gets 30+ haha.

 

mileage?

change fuel filter?

air filter?

tire condition and PSI?


you running 5w20 oil? a thicker oil can hurt MPG's

 

truck has 85k on it now. i changed air filter fuel filter spark plugs i run motorcraft 5w20 oil. tire pressure is where it should be.

 

Have you towed anything recently, or had a different driver driving it for a week or two? The reason I ask is that these 2004 are very sensative to changes in driving style and will adapt power and performance to closely match what it thinks the drivers intentions are.

You drive like grandma, you get grandma power and performance. You drive like a wild man, it will rise to the occassion.

It's not a linear relationship to how much you push the go pedal down, but how fast you move the pedal, under what conditions, how long you hold it there, how fast you let off of it. Floor it, and let off fast, the computer asumes that you want quick accelereration, conversely, if you roll on and roll off the throttle, and slow down slowly, the computer delivers what it thinks you want, mild performance (that equals better MPGs by default).

 

I got the same truck and before I was getting 18-19 mpg with stock tires and some times with my bigger tires. Now Im lucky to get 16. I have been trying everything. I havent changed anything except oil. I clean the air filter though. Thinking I need to get my cam phasers replaced tough

 

Since my transmision was replaced my truck has lost about 1.5 mpg across the board. The transmision hesitates then shutters between 1 and second gear shifts. Sometimes when i hit it sounds like the motor is reving up fine, but truck does not pull like it should. I think it might need some reprograming. Tryed different settings with the edge but had no change. After you had your tranny replaced did your milage drop then.

 

I had a new trans put in around the begining of the year. I think my miles went down before it went out though.

 

So i changed my fuel filter again and holy **** it ran out like muddy water....... ???? I changed it and filled it up with some seafoam in it before putting it back in.

 

might have to pull & flush the tank if your filter is plugging that quickly. Only takes a couple gallons of bad gas.

If you don't take care of it the problem could get a lot more expensive, $650-850 for the fuel pump / fuel sending unit & labor.

 

That was my next question on flushing a tank. I can not believe how dirty the fuel was... it looked just like chocolate milk lol... nasty nasty...

 

If the fuel was that dirty, it would be a good idea to run some fuel injector cleaner in the engine too. My Ford dealer wanted to charge me $100 to clean the fuel injectors on my '06 4x4 and I did it myself for a whole lot less than that.