It sounds like you didn't get it full, which as said above can make a huge difference.

 

well i got the thing filled to the rim and i drove 80 miles highway and 80 miles city and all i got was 11 mpg combine. that means the problem is not fix.
i replace the air filter, fuel filters, and clean the egr valve.
you guys think auto zone can ck the codes on this truck, its free.
what else could i ck.

 

autozone used to check codes here in cali but now due to the strict smog laws they will not do it anymore. Not sure if they will in other states. I was jsut told it was company policy that they didnt check codes anymore. But if they do where you live then go for it. Wont hurt nothing and you can find otu whats up with your truck. BTW have to ask. Do you smell any fuel while driving? Say if the fan was on or if you just have the engine turned over adn hood popped? About 2 months ago I was getting really crappy MPG. Found out that my fuel presure regulator was shot and leaking in the engine compartment.

 

i dont smell any fuel. i ck the engine compartment and and there is no leaks anywere.

 

NO idea what it could be. Seems you have checked everything that I can think of. take it to Autozone and have them pull codes if they can.

 

I was told to take it to get the processors flash on the truck (up to date).
is the dealer a good place to do this or should i find a private garage that does it?

 

The only place to get it flashed is FORD.

 

I just got my truck processors flashed (up to date) $110.00
The only difference i notice is that the transmission shifted a lot faster.
Before you did not feel the transmission shifting, now you can fell it going from first to second and third...
I hope is a good thing.
any body knows if the 03 and the 04 are the same programs?

 

I'm experiencing the same results as you, Gamaliel. I'm seeing around 9 city and 14 combined (freeway/city) ... if I am lucky! My 24 valve Cummins, with 4.10s, beat the stuffing out of this. I was getting 17.9 combined ... hand calculated!

Powerstrokes never have had a good reputation for mileage. There are always a few that push the gambit with their MPG stories ... and that's what they are, merely stories. I can see getting 16-18, if you're keeping her below 2000rpm and ALL freeway driving, but that's going to be it. Remember, these are big, heavy trucks!

If you're looking for a diesel that'll get you good fuel economy, find yourself a 12 valve Cummins. Those guys are getting an HONEST 20 MPG!

I have noticed that the harder I drive this truck, the better the fuel economy appears to be ... strange!

 

yep i just met a guy that has a 3500 chevy diesel with a plow.
he says he can plow all day on 4wd and he gets 13 to 14 mpg
how true it is, i dont know.
who to believe?