Just did a 7700-mile camping trip WA state to New England and back. On board computer gave me 12.2. Also used laptop to track all fuel used and came up with a flat 13 mpg. Truck ran great and really pulled the passes. Weighted in with slide in camper at 12,700 day before I left. Now if I could only stop it from trying to drive to the right all the time it would be perfect.

03 DRW 4X4 Rancho's,Airbags, 03 Lance 1030 Camper

 

My wife thinks I am obsesed when it comes to watching and calculating fuel mileage. I had a chevy duramax before that seem to better empty but loaded my cummins is better. With 31,000 miles on my truck I am now getting about 18 mpgs driving mostly 75 to 80 mph. I have found exactly the same as many others who have posted that 1800-1900 rpm's gets me up to 21 mpgs. I made a trip into the mountains never go over 65 mph and got 22 mpg's. As far a trailer pulling I have pulled a goose neck with about 12,000 lbs on it and was getting about 13 mpgs. My 7,000 pound 5th wheel gets about 16 under 70 mph. I hope that was not tmi.

 

Just returned from a trip to Knoxville (TN) and back (~80 miles round trip). Four-lane road most of the way, 55 mph speed limit. I drove 55-60 mph most of the way. Wind was light (round trip should account for wind anyway) and temperature was in the lower 60s. Reset computer at the start of the trip (computer is generally within 0.1-0.2 mpg of calculated value). Here's the result:

 

CCM, I am jealous . I hope my truck will hit that kind of milage. How many miles do you have on the truck? Thats good stuff-Steve

 

At 115 Kilometers per hour on a 630 mile run, I netted 21.8 calculated and the overhead said 22.4 with a Bullydog box on.

Not too bad and I have only 4,000 kilometers on the truck...half of which was hauling heavy. Getting a nice break in. ;D

 

[quote author=CTDinMT link=board=17;threadid=18536;start=45#msg193049 date=1065368364]
CCM, I am jealous . I hope my truck will hit that kind of milage. How many miles do you have on the truck? Thats good stuff-Steve
[/quote]

Steve, it has a little more than 10K miles. It's a 2500 4X4, HO, 6-speed transmission, 3.73, QC, short bed, and I have a soft tonneau cover on the bed. It weighs 7220 pounds per a certified truck scale with me (~200 pounds) and a full tank of fuel.