hey it's nice to see I am not alone. If you figure anything out, PLEASE let me know.

Thanks

 

My suggestion is, have your ECM re-flashed and see if that helps. If that doesn’t help try putting whatever stock parts you have back on.

I don't know if this will help but this is what I've found out so far. I purchased my vehicle in Va. and drove it back to Fl. 720 miles. Pulling an 18' dove-tailed trailer running 75 mph on average I got 16.5 mpg calculated by hand. (Do trust the lying mpg meter they are always wrong) I installed a volant cold air intake and had no noticeable change. Then installed a 4" AFE free flow turbo back exhaust and had one noticeable change. (NOISE) then I installed a Hypertech 3 stage programmer and noticed a fuel mpg drop. I tried this programmer in all 3 stages many times and found no difference, my mpg stayed at 13.9 on the highway or city under no load. I removed the programmer and the mpg stayed the same. I've had every test and diagnostic available ran on the engine & Transmission and found nothing wrong. The next step I had the ECM re-flashed at CJD Automotive and when I got the truck back it ran different, it had more power from the start as before it seemed to struggle or drag on take off. I haven’t had a chance to check the mpg yet but I will soon.

I've been told different things concerning the engine setups, performance and mpg. Most people say that changing the air intake is ok. As for the exhaust and the programmers they have conflicting opinions. I spoke with Cummins and I was told that the Dodge 5.9L engine needed the factory exhaust system for the engine to run properly. That seems to be one big conflict there; because just about everyone else says to it doesn’t matter or it should help. As for the programmers I have sold them used in the Ford 7.3 liter and had good results, but I've 2 dodges one gas 5.9 liter and one Diesel 5.9 liter and they have done nothing but things worse.

 

The 2004.5 engine is thirstier. 16 best on the highway. 10 pulling.

 

I think, but am not sure, you guys have the same engine as me. I have hand calculated and confirmed that my display is within .5mpg, which is nice.

My mileage typically is around 17-18mpg empty on the highway. I've seen as high as 21.5 recently for no apparent reason, other than my speed was way down following a transport truck (could have been drafting him too, but I figured I was too far back).

I removed my BullyDog as I didn't think it was doing much... I was right.

 

Cthulu......u have the 6 speed correct? I would subtract 2mpg for my auto. In north Dakota 2 lane speeds r 70 and interstate is 75 with the avg about 80mph. My trailer is a huge wind drag monster.

I think someone said it best awhile ago that it is still pretty nice moving a big truck like ours in the double digit mpg. My hemi was 14 highway and 6 towing.

I do know for the vs methanol uncan get an European emissions chip that significantly raises the mpg. I wonder if there is something for dodge. Oh wait there is. The turbo back exhaust.

 

A portion of your problem is the year of your truck in that anything produced by Dodge and Cummins after 2004 has had to conform with EPA mandates.

It takes very little time for the products and moisture factor created in the crank case to erode and dammage the injectors. A diesel engine is not designed to circulate and reburn these waste products.

Doing things to soup up yor truck only makes the condition worse. If your truck is out of warrenty there are after market ways to solve the EPA caused problems.

 

Tiger63, This is the information we would like to know about.

 

Nah, I wish I did. It's the 4spd Automatic. I too used to own a hemi and I agree, it was hard on fuel. My numbers match what you have above.

I've been told our generation of 5.9 CR has an in Cyl solution as opposed to the new trucks that have a much more complex to get all that carbon through and clog up.