LMM Fuel Economy

[crazydave01]

08 GMC CCSB. Front leveling kit only, 305/50/20 tires(actual height is 32")

Best tank on highway 14.8
Avg highway 13.9
Avg local 12

Hauled my motorcycle trailer today and got 8.2 MPG. It only weighs 4000 loaded. My 06 silverado with a 5.3 got 10 MPG everytime on the same trip, same trailer.

Diesel fuel 3.399 gal = very expensive and disappointing.

All mileage figured by GPS and amount of fuel pumped at the station. The DIC shows worse mileage than actual.

KD ECM on the way. Hopefully it helps

[FYRWOOD GUY]

my 2011 3500HD with the break in oil still in motor at 2560 miles is telling me via the dic that fuel mileage is 14.8 and seems to be climbing during this break-in time. i am going to run mobile devac elite synthetic diesel motor oil. i guess i should start keeping track of mileage the old fashioned way after i dump the break-in oil.





would like to read about other 2011's

[Mark Rinker]

Great looking rig...nice chainsaw/logging website!


www.MREBoatTransport.com

[JohnC]

Diesel fuel 3.399 gal = very expensive

Ah, for the good old days!

[prairiewind]

I have owned a 2002, 2004 and now 2008 3500 HD. Got 17 to 19 in first two. I have 72,000. on the 2008, got 17 when first purchased, now 12 to 14. When I take to dealer and they reflash I can get 19, this will las for a few tanks of fuel then back to 12 to 14. I can put my auto zone tester on and there will be no codes, I reset codes, even though there are no codes, and I go back to 18. I would like to put an edge cts and an exhaust brake on but would like to figure out what is wrong before I do anything. Dealer has no idea.

[DieselDavy]

Are you hand calculating?

[prairiewind]

Yes, mostly, I pretty much use this truck for trips, I can look at the fuel guage and the milage and tell what is going on. Last summer I had the fuel system cleaned and they reflashed at the same time. I made several trips pulling a 4 horse slant and got 13, a couple of months later I made the same trip empty and got the same, 13. I went back to the dealer and another reflash and back to 17 to 19 depending on how I drove. These trips are over I70 from Denver to Page AZ. I also have a 30' Montana and when everything is running right I can get 10 to 12 when in my lame mode I get 6 to 9. When I started resetting my codes, even though they don't show up it doesn't make a difference right away but after a couple of hundred miles I can actually feel the truck respond. The truck goes from sluggish to very responsive, you know exactly when it happens

[prairiewind]

I was sure hoping someone could let me know if they had the same problems, have tried to reset, anything.