Depends on conditions, anywhere from 15-19. 15 (maybe less) around town with the Edge turned up and goofing off, just over 19 on open flat interstate below 65 (I10 across Texas at night for instance).
Ive seen almost 20 on a road trip unloaded. Worst ive seen was about 14.5, but that was pulling our travel trailer and 4 wheeling on a hunting trip.
I have had 20.5 on a road trip unloaded. Average around 15. Sometimes less when I can't keep my foot out of itimp:
Unloaded, around 19 most of the time. Mixed driving. Unloaded on the road 65-70 it gets solid 19 sometimes 20.5. The trick is keep your foot out of it and keep the RPM below 2000-2100 RPM. The faster you go the worse it gets.
my computer has been reading 11 mpg since i got the truck, although the engine hasnt broken in and i havnt gone through a full tank it seems pretty far off from what you guys are getting. did the previous generation duramax's get better mileage as a trade off for performance?
Have you hand calculated it? Sometimes the computers are off. True, you'll get better mileage as time goes on, but you should still get better than 11. Try and calaculate it out by hand.
I just got back from an 1700 mile trip and averaged 18 with an empty trailer going down and 15 with a loadedd trailer coming back. Kept the RPM's in the 2000 range and was still moving along quite well. Unloaded in the city I get around 18 or so and have gotten around 22 on a trip empty.
So far with only 190 miles on it the computer is telling me 15 MPG, but I gotta get off the throttle and keep her around the speed limit and it would prob vastly expand my MPG LOL
Because they lied and it's really a gasser? No idea, never heard of a diesel that was doing that poorly. I would check the obvious, air filter, obstructions, etc. If that does not turn up something, I expect you'll have to take it in.
i get 22.8 empty when i keep it between 65 and 70. i pull 9500 lbs from california to nebraska and got around 14.5
poor mpg Im the one with poor fuel milage. i put a k&n air cleaner on it the same week i got it. i took it to chevy and they said nothing is wrong. and they did a glow plug update. it has 21000 mile on it when i got it. i pulled a 14000 lb 5th wheel from FL to PA at 60-65mph and got 8 mpg and i towed a little u-haul trailer to PA to ME and back and got 10 mpg. for a stock truck it suck. the computer mpg always says 13 mpg. and it is a diesel wise guy. one ton drw 4x4 crewcab 6.6 LLy auto can any help?
I have an '02 GMC 2500HD with the 6.6 D'max engine. I have calculated, at best, 14 mpg and approx 10 mpg towing the 5th wheel. What could be wrong?!?
