SFMETELKA

i have a 2006 dodge 2500 with the 5.9 cummins. i was getting between 18-25 mpg depends on how i was driving and what i was pulling. i had a fuel problem so the dealer put all new injectors fuel mainfold lift pump fuel pump - they replace everything that touched fuel. after they did this and my 12k in it the fuel went to 10.5-14 mpg. any ideas on what is going on.

Lost Lake

Well, you were getting crazy good mileage, now you are getting normal Cummins mileage. Sounds like they fixed the problem.

I suppose it could have been your injectors were putting too little fuel in the cylinders, or maybe one wasn't working at all. You probably didn't have as much power as you do now.

I know I can get better mileage with my Smarty Jr set on 3 than I can on 1. I have less power on 1, and I get less mileage. But when I stick my foot in it on 3, I have tons of power and the mileage drops like a rock.

So I'd say your power has changed (you may notice it when pulling or flogging a Ford) and your fueling is much different.

Who knows, your engine may last 800,000 miles now where before it could have spun a bearing at 85,000.

nelrod

Man I am sorry to hear it for ya, you must have a 2 wheel drive with a stick to get that kind of mileage on an 06. Anyway,I get about 11- 14 according to how I drive it, and that is empty. The most I ever got was almost 18 mpg driving it like I had an egg under the go pedal. On a trip once, I got almost 17mpg.


ANYWAY - - - WELCOME TO DTR!!!! FILL OUT YOUR SIG SO WE KNOW WHAT KIND OF TRUCK YOU HAVE, AND MEMBERS WILL BE ABLE TO HELP YOU OUT BETTER.

92'1stGen

Yeah that's some pretty high mileage for any truck. Was that hand cal. or what the overhead was saying? I get about 16 regularly in 50 city/50 highway driving, with some tanks close to 18.

Sandhopper

I get 18-22 around town in my 06' 4wd 3500 MegaCab depending on the weight of my foot. I have gotten 27 on the open flat highway fully loaded for vacation (no trailer). The only mod I have is the 5" exhaust. Sounds like a bus but has plenty of power to jump off the line. If I hook up the trailer (25' travel) my mileage drops to 12-14 mpg.

cromulius

Mileage claims should always be followed by either hand calculated or overhead gauge (almost worthless). Fyi I get 16-17 hand calculated around town which includes both side street and hiway driving.

05 Ram 3500 SRW

Just wait til the injectors get broke in i think. i got new ones in back and feb and my mileage seemed to be down about 4mpg on average empty and towing. i mostly watched the over heard, i know its a tad high and knew it from before and after. i did the odd hand calc to make sure it wasnt off.
but as time went on my mileage picked up. i started running power service too so maybe that helped. by summer time i mostly had my good MPG back and the truck will smoke when you stand on it to pass.

NickBeek

SFM, were you taking mileage from the overhead or actually hand calculating? My truck will get 18-20 with mostly highway or country highway driving. When I had and injector replaced it dropped off considerably. Then when they replaced all 6 with brand new sticks, my mileage started climbing back up slowly to where it is now. If they put all new fuel system on your truck and the mileage tanked that bad (hand calc'd) then I would guess they fouled up the install on the injectors or cross tubes. The other possibility if you were using the overhead to judge mileage before is that the flashed the truck with the latest calibration and the overhead is now more accurate.

Lost Lake

Can we get the overhead to be a bit less uh, optimistic? Mine is about 20% off. So if mine says 25 mpg, it hand calculates to 20 mpg.

It looks cool when someone climbs in the truck and says, 'Man this thing is big.... What kinda mileage do you get?'

I just point at the overhead......

NickBeek

What's even crazier is that the ECM keeps pretty good tabs on fuel economy. I had a guy check out my ecm with the StarScan tool. It showed a lifetime average of 17.8 mpg which was very close to my actual lifetime average at the time. So if the ECM knows what's up, the overhead "could" be more accurate, but I guess Chrysler would rather we have "feel good" gauges in our trucks instead of accurate instruments.

Lost Lake

Wow, That's incredible,,, So they know they are pushing bad numbers as a feel good thing...

Kind of like how a fuel gauge reads full for half the tank, then 3/4 for a hundred miles, then falls off a cliff....

SFMETELKA

all my numbers i got was by hand not the over head. i have ran the truck 30,000 miles since i had the work done and my mileage has been droping ever since. i all ways run power serv in every tank. i was getting 600-640 miles per tank and now i am lucky to get 325. i have low power(i can feel when i pull my 12' alum. trailer with a lawnmover). also the eng is louder than it was before. it seams to have more of a fuel knock sound. i have adj the injectors they were 40thousands off. thanks for everyones help so far.

NickBeek

Did you mean to say you adjusted the valves? There is no adjustment on the CR injectors. Was one valve off by .040 or all / many of them?

SFMETELKA

nickbeek i am sorry you are correct. i adjusted the valves. i am use to talking about a big bore eng. but the closest one was was 20thousands off. the reason i checked them was i could hear a chearp when it was at an idle. but they were all off.

AH64ID

I would verify that there are no fuel leaks, and no fuel in the oil. Something is wrong, you're mileage should be better than that. You're previous mileage was extraordinary, but your mileage now is a bit low..