Don't know about the 06 but my 04.5 dually with 4:10 gears got over 20 m.p.g. empty @ 70 m.p.h. easily. That truck was completely stock and had a kitty CAT too.

 

Does anyone know if the 2007 5.9 has the DPF on it or did the DPF come out on the new motor. If you are looking as the system how do you tell if it has a DPF on it?

 

The DPF wasnt put on until 07.5.. On the 6.7 cummins motor. Easiest way to know if its a 6.7 is to take a knee next to the passenger side in front of the rear tire. If you see a big canister that looks like another cat then you have a DPF.

 

I guess it must of been 03/04s that got the bad fuel mpg. I cruise 70 mph at 2300 rpm all day and get 15.2 mpg calculated by hand.

 

Did you pull the trigger yet TX? I bought the one in my signature about 2 weeks ago. I went round and round, Hemi, Manual, 68RFE, for a couple of months. I think I'd have probably been just as happy with the 68RFE. The only reason, I regret not going with the Hemi is because of the extra $11K drain on my bank account. After driving a Cummins for 9 years, I couldn't get excited at all about driving a Hemi.

 

I agree about not wanting to go back to a gasser. I dont think I could do it either. I have not yet bought a truck as I still have the one Im trying to sell. Plus I ship to OCS in three weeks and dont want to have to "test" something new to me right before I have to take off. It'll happen, just not right now.

 

The 03 and early 04s got great mileage. My 03 3500 SO, which was making 500hp got almost 17 city and up to 24 hwy if I drove slow enough. Driving my normal 75-80mph I usually got around 19-20hwy. I even had 315s on it too.
I did not drive around with it at 500hp though. Usually it was set at around 400-425hp for everyday driving....

 

Well this is a bit later than I had wanted but eventually did buy a 3rd gen. I found on 04.5 HO 4x4 QC LB. It came with a diablo predator and I drove it from Dallas, Ga to Quantico, Va and got right over 20mpg. Im happy with it and appreciate all the help!