Cummins fuel economy
 

Hi I just bought a 2004 Dodge cummins 5.9 with only 115000 km on just wondering how many km guys are getting on a tank of diesel. I'm only getting about 600 km in winter that bombing around town with a little highway but feel like I should be getting better. Even put in a smarty jr. Thanks

600km on a tank? so about 12mpg... I am getting 16-17 mpg / 26.5 kmpg

on winter fuel im at 19.2 currently with exhaust and smarty jr. has your fuel filter, oil, oil filter, air filter all been changed?

I've done as good as 24 mpg. Have to keep the rpm at or below 2000. A good, hot tune gives me the best mileage, as long as I keep my foot out of it. If all the driving is done on the interstate, it'll go 650 miles between fill ups. my upgrades are; Hamilton cam, 60 horse injectors, AFE cold air intake, 4" exhaust from the turbo back, Edge e-z, Airdog 150, and Industrial Injection phat shaft turbo.
Play with it a bit- intake, exhaust and good fuel filtering are a must. :c:

12mpg does seem lower than usual but then again if around town you are constantly stopping and going I can see that number easy. It's a heavy truck to stop and then to get moving again and you have 6 tires opposed to 4. what size tires are you running? If they're oversize you'll see about 1.5mpg less per inch added over stock. What rpm are you shifting at? I see about 15 in city- 18 ish hill country driving with 33's

It's not a dually just 4 wheels I only got 33 inch tires on there too. So I don't have a clue

I've gotten 24 MPG (HAND-CALCULATED!)...but this was doing 60 MPH on interstate for three hours.
My average range is 16-18 MPG normally. That's a mix of heavy right-foot, some trailer-pulling, and the rare slow, easy days. I rarely drive through city spots, though.

I'm pulling about 22.8 MPG at 65 MPH with cruise control on. That's with the 80 psi cold tires inflated to 70 psi. In town about 17.5 to 18.5.

The 33 inch tires definitely hurt mileage.
My 05 is bone stock, get 19-20 highway running 65-70, if I drive hard it does 16-17.5, so how do you drive it.

Dang all of you are getting way better than I am. I have a 06 3500 on 35" tires and I get 350 a tank which is 12 MPG.