Horrible fuel mileage
 

2004 powerstroke CC 4x4 stock besides the sct. I am only getting about 11 to maybe 12? Anyone got any ideas to get it up a little? i am not expecting alot out of it but with like a little better

what size tires?

When was the last time u serviced the truck? is this a new thing or has it been happening for a while now?

Tiers are one size bigger than stock and yes i think it has went down some since i have had it, and it is not do for service until 3000k more miles and last one i did oil with roteala and did both fuel filters. just replaced FICM befor christmas

What altitude do you live at. Don't laugh, when I get 13 mpg here at my hut @ 4000ft, I'm getting 15 mpg at my mom's at 1300ft.

I was getting 10.1 on my 03 but after replacing the hpop cleaning the egr replacing both fuel filters doing an oil change doing the blue spring mod two new batteries and driving like a grandma Ive made the slighest dent in my mpg... Almost $2500 later, parts only, im now getting a whole 10.2 mpg thats a whopping .1 increase hahahaha I'm gonna be checking my ficm pretty soon though. I have a feeling its seen its days

I've asked your question a few times now and ill tell you what every one has suggested to me. And thats check your ficm there is a write up on this site to walk you through it

Also are there any other things going on with your truck ie. sliggish at take off, sluggish period, hard starts when cold things like that

Sell it and get a hybrid.

Eric has one of the best FICM's I've ever used before, I've been trying to get it back from him! :tttt:
I know it's not that...

Eric, remind us all what is done to the truck too please. Are you filling the tank up all the way? Like so you can see fuel in the filler neck? Does the truck seem to run ok? What kind of driving do you do mostly? Do you tow ever?

Yeah the FICM is awesome! And I live in Florida. Yeah I fill it completely up every week. I dive pretty good most the time every now in then I will strech her out! But it was serviced 3k ago and I cleaned the turbo right befor I put that FICm on mike and cleaned the exhaust presure sensor and tube. Just seems pretty low seems like I was get 13-14 when I got the truck

Make sure your front hubs are in the auto position, I get terrible mileage when mine are in the locked position, some of these fuel mileage totals have me wondering.... I get around 18 to 20 mpg with mostly highway driving and being bad at times, and highway driving is at 75-80mph and that is also considering I let my truck warm up for at least 10 minutes before I leave the house, just took a trip to florida line,700miles one way, and there and back I averaged 24mpg for the trip but I kept the speed at 5 over the speed limit.