I know you cant get an acurate MPG on one tank but..............................The day I bought my truck, the dealer gave me a voucher to go and fill her up.




I filled it to the point to where I could just see the fuel at the bottom of the filler neck.


I ran 350 miles (still had 1/8) tank left........Filled it to the exact same point on the filler neck.

Took 20 gallons on the nose..............17.5 MPG on the first tank seems mighty darn high....But I aint *****in.....I have a base model truck, so that is calculated by hand.






And NO......I did not baby it....I tend to break a vehicle in the way I am going to drive it..........That 350 miles was 100% around town.


Hell of alot better than the 9 mpg I was getting on my 04 2500hd gasser.

Congrats on the truck! MPG's on the LLY are respectable, some will disagree. JJ

I like the MPG with my new truck as well!! :ro) Much better than my 2000 Crew Cab Dually 4x4 with the 454 & HD trans..

VR :)

Hell of alot better than the 9 mpg I was getting on my 04 2500hd gasser.

I fully agree...I sold an 03 2500HD with the 6.0...wow what a difference. I could get no better than 10 mpg in that truck. My mileage now keeps going up.

I fully agree...I sold an 03 2500HD with the 6.0...wow what a difference. I could get no better than 10 mpg in that truck. My mileage now keeps going up.











Mine was also the 6.0


I tried everything...........................K&N....Dual exhaust.....even thru a tornado in there out of desperation..........It just sucked on gas.

that is too funny... I tried tornado, K&N, muffler, headers, Hypertech...nothing worked.. LOL.. when my gas bill started to be more than my actual truck payment I knew it had to go.

enjoy the new truck

I am also pleased with the MPG of my DMAX. I also traded in a 02 HD 6.0L. But I guess it got respectable mileage compared to ya'lls at 13/15. My DMAX has been getting 17/19!!

Mine is totally stock, drive around town some, but mostly highway. About 7000Mi. Getting 14.6 average right now. Of course out on the interstate am usually cruising 75-78 mph. maybe I better talk to the service dept. about this.
Doug

With 5500 miles on mine I'm in the 16 -17.5 MPG range not babying it but not beating it either in mixed driving. Winter fuel has cut me down some though.
Rob

You guys are killing me with your MPG/s. Mine has 8500 miles and I'm lucky to get 14.5 hwy @ 70mph. Usually 13 around town and I don't push it. The bumper and winch weight in at about 300lbs and tool box might be 100 but I'm real dissapointed in the dmax mpg. I have a buddy w/ 04 ***D powerstroke with basically the same setup I have and he consistently get 17/18. I keep 50psi in the front and 45 in the rear on goodyear 305/16 ATS. Is there anything I should have the dealer check to see if I can improve this.

I just got back from an all highway 1100 mile trip. Got 20.5 mpg unloaded. Dropped a 10,200 pound boat on the back and brought it back 1100 miles and got 12.0. That was at a steady 70 mph both ways. I couldn't be happier if I tried. Also, the power is unreal. I pulled 7% grades at 70 with the cruise on and it never shifted out of overdrive. This is a stock 05 LLY. I was thinking about getting a predator, but now that i've towed with it, I can't see why.

My last diesel was a 6.2 suburban, so I'm not used to having 'REAL' power. This thing is great......

My 05 is getting 17-18 and I have about 5K on the engine. the first couple thousand miles I was getting 15-16. I do alot of hwy driving probly 70% hwy 30% around town. Love it!:ro)

17,700 miles on my 04 LLY and 17.7 average over the total miles. I am very happy! My 01 LB7 averages around 14.6.


I also had a 01 6.0 got 12 to 13 and 5.5 towing. I get 14.5 at 70mph on the HWY with my LLY.

Yes hand calculated aslo my DIC is very close to what my hand calcs are.):h

You guys are killing me with your MPG/s. Mine has 8500 miles and I'm lucky to get 14.5 hwy @ 70mph. Usually 13 around town and I don't push it. The bumper and winch weight in at about 300lbs and tool box might be 100 but I'm real dissapointed in the dmax mpg. I have a buddy w/ 04 ***D powerstroke with basically the same setup I have and he consistently get 17/18. I keep 50psi in the front and 45 in the rear on goodyear 305/16 ATS. Is there anything I should have the dealer check to see if I can improve this.
Did you account for your odometer turning slower due to the larger tires.Your 305's are about 12% taller than your stock 245's. Multiply your total miles travelled by 1.12 then do the mileage math.

I have checked my mileage around town I have gotten 15 mpg that last three weeks like clock work it never varies. I get about 18 mpg on the highway at about 70 mph. I hope i will at least get about 12 mpg towing my 10,00lb fifth wheel. Still stock but I am thinkingn about a predator. 2004.5 lly

I too traded an 02 2500HD 6.0l ext cab for the cc duramax.

17/19 mpg 40 mile roundtrip to work. DIC usually in the high 19 and 20.x (just wish it was true).

Towing the #3800 boat 12.5 - 14 mpg. Got a 15.5 towing to Alexandria , LA from Katy, TX DIC was reading 16.9. Very flat drive.

I have a 04.5 and am seeing what I consider to be crappy mileage. 9 mpg in city and only about 14 - 15 on the highway. Dealer here dosen't have a clue what to do or where to start. Says that is not bad. I am thinking a little differently. Anybody got any suggestions. The engine runs smooth, plenty of power but does smell a bit more then when new. I have 7000 miles on it. Thanks Jeff

yea! The speedometer. Your milage calculations are probably way off due to the non stock tire size

i get around 12.5 in town on mine and about the same on the interstate driving about 84. i did make a trip once on slick roads driving 55 and got 18.5. my father gets about the same on his. i here these guys saying they get these high numbers all the time. they all say they dont baby it but i think they drive down hill both ways. i can understand their being a difference between trucks but when some people say their pushing close to 20 and driving nomal i dont beleive them.

An avg. of 17 MPG's seems to be the norm reported for the LLY. I drove mine very delicately for one tank trying to get close to 20 and couldn't even come close - stock.

on my 04 lly, for the first 55,000 miles, I averaged about 16 - 17 mpg. I mostly drive highways around 80 - 90 mph. Very little city driving as you can tell by the miles on my truck. I will soon buy a Predator Diablo Sport to see what extra mpg's I can get. I have almost 59K on my truck now and now have the 285's on it, Man I love it. MPG's don't seem good now, but that is due to the truck needs to be calibrated for the new tires, hence more need for the Predator, in my eyes.

what size tires does your buddy with the powerstroke have