'04.5 mileage improvement?

[2broke2smoke]

a freind of mine purchased a cummins after hearing me brag about all the good luck i've had with them throughout the years ...



he purchased an '04 325hp 48re 4wd 4 door short bed ... loves everything but the mileage ... best of 11mpg on the highway empty



he lives in Hickory, NC and recently gave me a call that went something like "hey you work on these things for people ... what can i do to get 15 mpg?"



told him that an almost 50% increase in mileage wasn't going to happen, so he asked me what he should do for max mpg ...



i told him to straight pipe it and put a box on it ...



he didn't like the way the wifes sounded straight piped so he wants a Stainless straight through exhaust ... i told him silverline 4" should help him



i've got two questions for you guys



is 11 mpg normal (he is going to call me back with gearing info)?



what box would be best for mileage only?



he doesn't care about adjustability ...



anyone know O'Pooles #

 

[Matt400]

That mileage is horrible. I get 17. 5 to 19 depending on where I am driving and thats hand calc.

Motor is stock except for cam and the mileage seems the same so far after the cam.



Have him check TSB's for a mileage flash, something is wrong with it. The key I have found is keeping the R's under 2K.



A couple TSB's that will effect mpg's that I know of are:

http://dodgeram.info/tsb/2004/18-007-04.htm

and

http://dodgeram.info/tsb/2004/18-037-04.htm



edit forgot to mention I did increase timing 3 degrees at the tone ring also.

 

[klenger]

I get 12 MPG towing my 10K 5th. His truck is broken. Check TSB, fuel filter, injectors.

 

[CGresswell]

18 to 20 empty

I'm 2x not 4x4. And I'm stock with a full shell in the back.

I recently hauled an enclosed big box trailer that had about 6-7000 pounds inside to Cedar City from SoCal. I got 10. 9 the last of the trip after Vegas (it was windy) to Cedar. Coming back (empty) I averaged 16. 5 the whole trip even with the winds.

Around town empty and no trailer, I get 18 to 20, when I don't put my foot into it.

I did get my truck "flashed" by the dealer last year and that DID give me the big increase. I was getting 14 or so before that.

Dick

 

[HDaniel]

I usually get 18-19 mpg (hand calc) on the highway, but that's running about 70-80 mph. I have taken the extra time to do my best not to break 60 mph on a couple of trips, but that only yielded about 1 mpg gain overall. In town, I get anywhere from 12-15 mpg (closer to 12 most of the time) I just can't seem to get to the next stoplight quick enough. Tell him not to baby it, and to get out and flog the crap out of it.

 

[steved]

I can get 20mpg driving sensibly... I have gotten 21 a couple times... thats with 4. 10s.



11mpg sounds low... as stated, hand calc it... then check for codes or TSBs.



steved

 

[grfraz]

I get 15 hand calculated and overhead with this truck:



04. 5 QC 2500 4x4 automatic, and a 4. 10 LSD rearend. BFG AT 315/70/17's, Stock air filter box w/the New Amsoil Air Filter and a Torque Tube, MBRP spiral flow muffler, and Xillaraider XZT



I'm no light foot, if I'm driving I'm generally driving fast. My overhead is dead on with hand calculations everytime. I've frequently seen 17. 5 on interstate trips.

 

[JimBob24]

When new mine got about 15 mpg. Now it is getting 18 mpg with 26k miles on it. The Rokktech helped by about 1 mpg. The tsb for white smoke and mileage also helped maybe 1 mpg. That is with mostly rural driving around 50-60 mph. On the open road I get about 11 mpg towing my 12K 32' FW. A lot of stop & go city driving will drop mileage to 16 mpg. I would agree that 11 mpg is a serious problem.

 

[2broke2smoke]

thanks guys ...

 

[AMixon]

thanks for this thread! My DRW was only getting 13. 9 as a best (it was getting better, I guess it is begining to break in at 50,000?) and then I went in and had it flashed. Now empty at 70 mph it gets 18. 4. Hell, that was like adding another fuel tank! Thanks guys for the good info!

 

[FCecelin]

15 around town with the 6 sp and between 10 an 12 towing the 5 th wheel

 

[Bekim]

a freind of mine purchased a cummins after hearing me brag about all the good luck i've had with them throughout the years ...

he purchased an '04 325hp 48re 4wd 4 door short bed ... loves everything but the mileage ... best of 11mpg on the highway empty

he lives in Hickory, NC and recently gave me a call that went something like "hey you work on these things for people ... what can i do to get 15 mpg?"

told him that an almost 50% increase in mileage wasn't going to happen, so he asked me what he should do for max mpg ...

i told him to straight pipe it and put a box on it ...

he didn't like the way the wifes sounded straight piped so he wants a Stainless straight through exhaust ... i told him silverline 4" should help him

i've got two questions for you guys

is 11 mpg normal (he is going to call me back with gearing info)?

what box would be best for mileage only?

he doesn't care about adjustability ...

anyone know O'Pooles #

Start with an ECM flash for TSB 18-037-04. It deals partially with bad mileage. That's a free thing from the dealer.
Most of the programmers out there have a lowest setting that improves Hp and mileage. Don't waste money on replacing your factory 4" exhaust with an aftermarket 4", just do a muffler change(and the cat delete pipe if you don't care about Fed. smog law)
Cheers
Mike
###

 

[D.Inman]

I get 14 around town and 18 on the highway. Around 9 to 10 pulling 34' 5er.