MPG WTF

[KUGSS]

After buying my first diesel (05 6.0 cc) and getting it running and driving it fot a week (about 400miles), this thing gets the worst fuel milage i think i have ever seen! My firts fill up i got avg 9.26mpg driving normal little highway and local. So i run some diesel clean and get 10.25 on my next fill up. On the other side of the pump was a guy with a 06 6.0 cc so i ask him what he gets '' if i drive normal 16 and driving hard 14''. This is my first diesel and i know that towing they cant be beat but this is ridiculous. I have always been the guy that says gas motors are hard to beat for your everyday truck but i didnt think it would be this bad. If this thing doesnt get any better this truck is going on the chopping block and i will get a big block chevy and get the same milage with less noise.
Rant over.

[2003kingranch]

are you hand calculating mpg or are you using the lie-o-meter. y truck gets 19-20 mpg consistently but according to the lie - o meter i get 13

[99 Stroker]

What all did you have to do to "get it running"? If that's hand calculated, you've either got one helluva lead foot or something aint right. Hope it gets worked out for ya, don't toss that Cheby in there!

[dazdillenger]

Being your first diesel, you don't know how to drive it yet. Subtle differences in technique can make a HUGE difference.

Also, "get it running". Please explain. There are many things that affect fuel mileage, I can list them once I know what you've already done!

[HAM_RADIO_MAN]

Mine get 16 city and 20 to 21 hwy if 65mph or under. If you run in tow/ haul mode in town it will kill your mileage as well. You have to drive it like a heavy truck not a sports car.

[KUGSS]

As for what i did was to reinstall a new injector harness, turbo oil feed line, blue spring, 6.4 banjo bolts, and oil and filter trans fluid and both filters, both fuel filters, and coolant flush with fleetchage coolant. The truck does have a lift kit but there is not way that it can kill my milage that much. the truck dont blow any black smoke not evean a little when i take off from a stand still. And i drive very normal maybe even slower than my 1500 silverado and that got 15-16 around town and 21 or so on the high way with the lift kit.
finally got one!

[dieselmatt]

You could have a bad strategy. Some of the strategies get good fuel mileage and some don't. Do a search for strategies on here and you will find a lot of information as to which ones are good and which ones are bad.