Chevy Duramax Fuel mileage

04 3500 duramax efi live towing tune.Get 650-700 km empty and 450 towing out of a tank. Not sure what that is in miles

Non-towing - driving 60 - 20 mpg, driving 70 - 18 mpg
Towing - driving 55-60 - 11.5 to 12.0 mpg, driving 65-67 - 10.0 to 11.0 mpg.

Mileage towing will be impacted by head winds and hills/mountains.

My 2011 D/A gets about 1/2 mpg better than the 2005 D/A I had - 5 speed Vs 6 speed allison.

Previous DAs:
2005 Chevy Silverado 3500 LT CCLB LLY SRW 4X4
2004 GMC Sierra 2500HD SE ECLB LB7 4X4

The Duramax/Allison will tow that size of trailer without any problems but you'll probably be exceeding the GVWR of 2500HD truck (One of the reasons I traded my 2004 for a 2005 and the 2005 for a 2011)

If you can get a newer (2011 and newer) 3500HD SRW. GVWR is 11,600 lbs. The newer 2500HD has a GVWR of 10,000 lbs.

The "older 2500HD has a GVWR of 9200 lbs and the 3500HD has a GVWR of 9900 lbs.

My '06 D/A 3500, with the heavier service body, and with 124,500, is getting 19+ running empty and 12.5 towing our fifth wheel.
I tow at 60-62 mph.
I have tracked the fuel mileage since we bought it new.
Average mileage is 15.8.

I've had four 3500's pulling a 20K trailer. Always get around 10 mpg. I get 11-12 when pulling a 3000# trailer. Maybe 16-18 not towing.

We have a 3500 dual DRW,4 wheel drive,duramax/allison so it is heiver than the 2500hd I get 9-10 towing with the trailer around 14K . I dont think your going to get much more than 10 towing. I get 14 avg combined city /highway driving

rrbowman wrote:
I am looking for an honest answer from actual campers. I am considering buying a used 2005-2008 Chevy 2500 w/Duramax with a Alison Tranny to tow a 10,000 - 11,000 Fifth Wheel. Those of you that have a combo similar, what kind of mileage do you get when towing and not towing? I know that is subjective because of driving styles but I consider myself a driver trying to get the best mileage. I have been told 22mpg around town and 16-18 when towing, is that possible?

Someone is dreaming! In the 2007.5 models (new body) fuel mileage decreased. And no truck gets 16-18 towing. Towing mileage for all the different diesels varies between 8 and13.5-14 depending on lots of variables. I get around 12-12.5 average with truck and trailer in my signature. Chris

I been told that some folks like to brag about their fuel mileage, but that is one tall tale.

I've got an 06' 3500 DRW, and get 16/17 open road, 9/10 towing
Don't drive it around town, so don't know "city"