I got an overall average of 12.5 MPG with my 2004 Durmax 2500HD towing a travel trailer from Northern Michigan to Mission Texas by way of Lexington Kentucky. 2300 miles. Once I got south off winter diesel I had a 13.5 MPG day going approxamately 65 MPH. Trailer and truck payload of about 5500-6000lbs. Tow haul with the Allison is fantastic and doesn't negatively effect mileage. Going faster than 67 mph mileage nose dives. So does accelerating hard. 64-67 MPH seems to be the sweet spot. Range is exactly twice what I had with my gasser and it handles 500 times better. Can barely feel the trailer in a high wind. The 2500hd is a nice rig. Just putts along at 1800 RPM. Very happy.:D

At 1800 RPM what is your MPH. On the 02 LB7 I had at 70 MPH the tach read 2000 RPM, on my 04 LLY the tach reads 2200 RPM at 70 MPH. I have complained about my fuel mileage since I bought it. The dealer said there is nothing wrong. It is because of the increase in HP. I get 2-3 MPG less pulling the same 27 ft. fifth wheel camper.

1800 rpm is in the 60-67mph range depending on hills and wind. Tach is really not that easy to tell. Wind has a huge effect on MPG. Rough road surface and anything but flat do also. MPG goes down really bad above 67mph. Less than 11 MPG at 70 even on a nice flat highway with no wind. I will be keeping around 65 mph or below from now on because trailer gets too beat up with the horrible condition of most interstates. 2200 at 70 mph seems high?

....... on my 04 LLY the tach reads 2200 RPM at 70 MPH. ...........

2200 RPMS pushes my '05 at 70MPH while in O/D

My '05 does 2200 rpm @ 70 mph also. These things do pull sweet don't they?!!!!

Sam,

Is your 2004 truck an early 2004 with the LB7 engine, or is it the 2004.5 with the LLY engine?

Thanks.

I have the LLY.

I've got an '04 LB7 and tow a 5K# travel trailer, and get about 13.5mpg average on it. Once on the flat with a tailwind I was getting nearly 17mpg (didn't last long though). My old F-250 with the 460 was getting 7.5 to 8.5 unless I was going up a steep pass then I would get 4-5mpg (D-Max gets 7-8 mpg).
Family thinks the the diesel is quieter going up the passes too (sleep on Friday nights). Very happy towing with the thing. Did break some dishes once hitting a bump going too fast. :eek: Had to slow down.

I wish I could get that mileage! Maybe it's because I'm carrying a bigger package, er, load.):h

Averaged 12.8mpg towing on a 7k mile trip to Wyoming and Montana last summer. It sure was nice to travel a decent distance between fuel stops (versus my previous Ford Expedition). Also huge difference in the mountains ):h

I have only checked the MPG when my 04 LLY was empty: I got 18.9 MPG.
I understand when members talk about the towing. I live in Oregon and cross the cascade mountain range and the coastal mountain range on most camping trips. I have a crew cab shortbed pulling a 10,000 pound Komfort trailer and I can't believe there isn't a mountain stretch in the state that slows me down to less than 65 MPH on our outings. Of course I'm also sure that the fuel economy goes downhill as I'm heading up(but it would probably improve if I didn't use my lead foot).

I only have 3600 miles on my 05 lly, and get 14-16 towing my 7000 pd 5er at 70-75. In the city no towing I get around 14mpg, and 17-18 on the hw at 75

Still the lb7 gets better mpg, from what I have read on this site.

My 05, 3500 dully utility body loaded is getting 12.5-13.0! My 02 got between 16-17 but that wasn,t until about 18,000 miles!

And yea "THESE TRUCKS ARE SWEET"!

I have a 2,000 lb self contained camper and a 31' 3 axle race trailer that weighs 11,000 lbs. I am looking forward to my first trip with my new truck... hopefully I will get as good of mileage as you are getting. That big fuel tank for our trucks is looking pretty good too.. :ro)

VR

I haven't done any towing trips with '05 yet but I'd like to see at least 13 MPG. My father-in-law is a true Dodge guy (that's all he owns). He recently towed the same size trailer that I have (24' enclosed car hauler) and saw about 16 MPG with hard driving. My supercharged 8.1 Suburban and naturally aspirated 8.1 Silverado HD saw 7.6 and 7.8 pulling the same trailer so anything over 10 will be great for me! I'm usually running between 70-75 while towing.

Tbyrne, good to see you on this forum as well.. ):h

I was lucky to get 5 mpg towing my setup with my old gasser 2000 crew cab dually with the 454 and HD 4 speed auto.. :eek:

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