LMM Fuel Economy

[pamax]

I have a 2009 Crew Cab HD2500 with 587 miles and I am getting up from 14.6 new, to now reading 15.2 on the computer. My 01 would get a solid 17 on the same trip running at 60 mph. So far can not tell if it went through regen or not but the tail pipe stays clean.

[WyoDutch]

2009 3500 4X4 Xtended cab SRW. Running 1/2 ounce of Opti-Lube XPD per gallon of fuel.

19MPG, running our 65mph speed limit over all sorts of terrain.

[havenopower]

My 2004 gets like 10mpg with all the mods but my 2006 lbz gets no better than 12mpg in town stock with no cat of muffler. tried a super chip junk

[WyoDutch]

At the 6,000 mile mark:

Non-synthetic motor oil
8 ounces of Opti-Lube XPD per 40-gallon tank of fuel
No bed cover or other addons.

Just did a run to Texas and back (3,200 miles). Drove the speed limt... ranging from 55mph to 75mph. The last 400 miles, had 500 pounds of bagged corn in the back.

Overal mileage came in at 18mpg for the trip.

I'm pleased.

[EdHale]

I drove from Atlanta to Titusville, FL yesterday (475 miles). All interstate and all at 75 mph and my mileage was 36-37. Seriously.

Oops! Wrong vehicle. I was driving a 2007 Chevrolet Cobalt.

[ororke1]

I got 19.5 mpg on a recent trip with my 09 Siverado. 6000 miles on it, 68 mph empty. Around 15 local driving.

[nomad03]

I will get 17-18 hiway at 75 with no trailer in tow, if I am pulling ANY trailer from a small utility to my 29 foot rv my mileage will drop to 8-11. I am not very inpressed with my towing mileage. Power is great.

I am running 285/75/16 and have had GM reproram the system, also a K&N air filter, and a supper chip programer. I can set the programer on any setting and it will not effect my mileage.

I have 25k miles on the truck.
is this nomal mileage for this truck?

2007.5 LMM

[richp]

Hi,

A couple of weeks ago, I did Chicago to near Grand Junction, CO, with my '09 LMM.

Actual calculated fuel economy on the last two legs of this trip (topper on truck, cruise control on 65, short stop-off tooling around in Denver), was right at 20 mpg. I know from prior trips that running without the topper costs me about 1.5 mpg on this same route.

FWIW.

[Chevy Boy]

I been using this Excel file for 5 years now with some modifications and it works really good and it's accurate..........been averaging 19.6 mpg on my 2007 Silverado LT 1500 over a 3 years period.

http://www.uklegacy.com/forums/index...e=post&id=2651

[Runaway_Dmax]

I will get 17-18 hiway at 75 with no trailer in tow, if I am pulling ANY trailer from a small utility to my 29 foot rv my mileage will drop to 8-11. I am not very inpressed with my towing mileage. Power is great.

I am running 285/75/16 and have had GM reproram the system, also a K&N air filter, and a supper chip programer. I can set the programer on any setting and it will not effect my mileage.

I have 25k miles on the truck.
is this nomal mileage for this truck?

2007.5 LMM

I do not believe your dealer can adjust a DMax truck to your tire size - the ABS system yes they could, but for speedo - no.

If you still have the DPF in place, your programmer is causing the truck to regenerate more often and will result in lower mileage.

Your K/N filter is a big no-no for diesels. Yes it may allow more air into system, but more dirt as well. There have been independent tests done that show the stock air filter does the best at stopping dirt.

My truck is an 08 CC/long box and its hovers between 18 - 19 mpg and towing my 28 ft fw and atv trailer in tandem 10 - 12 mpg. I hit the magic 20 mpg mark once in the 38K I have owned the truck.

[BMDMAX]

I recently completed a round trip from Atlanta, GA to Loyal, WI to pickup my LB7 race engine from Kennedy Diesel. We burned 105.4 gallons of diesel over 2,137.2 miles for a trip average of 20.27 MPG. The highest leg was 21.0 MPG and the worst segment was 18.8 MPG. All cruise speeds were 73 to 78 with some bursts in the 80's. The 18.8 segment was bumper to bumper rush hour traffic in ATL.

All mileage was hand calculated.

This was with the KD Tow Tune ECM and DPF delete with the KD four-inch exhaust. Everything else is stock on my 2008 LMM. Very happy with the KD tuning on the LMM.

I highly recommend the KD tune for those wanting to bump up their mileage on their LMM.

[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.