A little over 12k on my F450 w/4:88's......like you all, I'm happy with it...P-poor mileage and all. Guess if I wanted 40 mpg I would have bought a Jetta, Focus or other car that would get caught in my grill!

Latest "Recall" flash seems to have ate into my 11.5 mpg average and that I'm not really happy over.

Running my 2nd tank full of Bio through it......quieted it down even more. Seems good to go thus far. Any other reports on burning the french fry fuel in a 6.4???????

 

Just wanted to add my .02 cents, coming from a number of Diesel pick up 1 tons and being involved with a professional Transport service delivering RV trailers all over the US, and Canada...pulling all kind of loads and using tuner products, and additives, I think I have been around the block. (one time... I was driving to the Artic Circle and the temp went down to -54 degrees and no cold start problems with heater attached) I had a HO 04.5 Dodge Cummins 4x4 with 3.73 gears and 6-speed manual, crew dually, removed the back seat and made a storage/sleeping area. Put about 75,000 miles on her in 7 months, including delivering the crappy FEMA trailers to New Orleans) and absoultley had zero problems and many times pulled over 16,000 lb loads, averaging 9 to 15 MPG, obviously depending on the trailer. That vehicle took about 15,000 miles to actually get some decent mileage...
I purchased an 08' 4x4 F350 ext cab, short bed, Lariat a couple of months ago. Ford Die Hard and like the idea of the lock out hubs with solid axle!!. 1000 miles on her now and according to the Lie meter (no hills) averaging 21 to 22 running (acutal calculated was a mile less) 75 MPH at 1850RPM with the 20" wheel package, and 3.73 gears... As other people have discussed, the trick is to stay out of the boost and keep the RPM down. I loaded my slide in truck camper (weighing about 2200 lbs in bed) and lie meter went to 12 to 13 MPG at same speeds (problem here is not the weight, but like driving a bill board down the road.)
I am pleased with the truck so far, handles great, smooth ride, brakes are good, haven't pulled and heavy trailers yet. Fit and finish is good and the interior is very quite. Not happy with the regin operation though, the more you idle the more it goes into that mode... looking foward to some mods for that in the near future...

 

Tropheytruck...curious as to whether you have the 6 speed manual or 5 speed auto?

 

I wish I could stay off the boost. Unfortunately, I live in the mountains and keeping the turbo pressure down is impossible.

 

I couldn't agree more on what a great truck the '08 is.

I was hesitant to buy an '08 even though my '05 was such a piece of **** because it was paid for and I wasn't looking forward to having a payment again. Man was I wrong in waiting, it's night and day difference. I love the new truck. Even the fuel mileage isn't that big of deal, I'm seeing slightly better than most people post and my '05 only got 12MPG anyway. Besides, I believe if you can afford a $50K truck, you should be able to afford the fuel...

 

Ya what he said............ 8-)

 

Stevensm... I have the Auto trans in my 08' Ford