just wanted to see what kind of fuel mileage ya'll are getting. love the truck, lots of power, but bad fuel mileage. 12-13mpg. at 600mile on it so far. 2010 3500 DRW crew cab 6.7l cummins, auto 4x4.

 

My first tank full was 15 mpg driving back and forth to work. It is mostly highway but a lot of city driving. I was really watching my spped and taking it eazy. My average hasn't really gone up because no I drive normally and keep up with the flow of traffic. Much better results on long trips. All and all it seems to be getting better with 8k. I have the 373 gears.

 

i recall seeing in one of the diesel magazines that the dually they tested was a couple mpg lower. more wind drag, weight and rolling resistance!
BTW, I just passed 1100 miles and I see 14-15 on mine. Better if I stay in the flatlands!

 

I have a 2010 2500 crewcab 4x4 with 3:73s and about 7500 miles. I've seen a best of 18.2. It does seem to be getting better. Thinking hard about doing away with egr and dpf. Would like better mileage, but other than that, I love the truck.

 

Matcom - 18.2 is pretty good. My friends 3500 08 manual does about the same. Best way to get mileage (and I have stated this before) is to hook the biggest load you can to the truck, preferably when it is new, and work it hard on a steep hill if you can. But alas some of our nations have lots of flat land where some of us live. I recommeded this procedure to a fellow at my local dealer and he improved his mileage by 10% and stated he saw a power increase as well. All of my 5.9s benefitted the same way.

 

I too have a 2010 2500 Crew 4x4 (LB) with 3.73's and 34's, and about 5K miles. Just came back from a 360 mile trip where I stayed between 70 and 75 most of the way, until doing a mountain pass where I pushed it uphill at 65 -70. Got a combined 15 mpg... Not unhappy, as my '06 was about the same with 4.10's and 35's. Have been able to get up to 18 when ONLY on flats and keeping at 60 to 65 - but like to go faster and like those hills!

 

This is an issue i am having now, I love the 05, want more cab room. My wife has a Nitro, best friend has a Trailblazzer SS, which gets killed by the 05. Every road trip we go on my truck is the transportation. Looking at a 2011 crew 3500 dually, auto with the 3;73. Would like to know what milage this truck would get empty, and if it would be wise of me to wait for the SCR system in 2012, have heard it boost economy also heard not worth the cost vs increased milage. Would a 2011 with full deletes, which is my plan, obtian better economy while running better??

 

I'm getting average of 17-18 highway and 15-16 in town. Not bad IMO from my previous 08'.

 

What is the SCR system for 2012 all about??

 

how about accuracy of the EVIC display for mpg? Over the last few tanks I have seen about 15-15.5 on the display, but my hand calculated numbers are .5-1.0 lower. 14-14.5 using the odometer/tripmeter.

 

with my modifications I am getting 21.5 hand calc through the mtns of Colorado while my comp reads 22.4

 

There's potential errors in hand-calc'ing the MPG - how far up the filler neck you fill it each time can change (the reference stop) due to not being able to see that, due to expansion and contraction of diesel based on it's temperature, due to the point a pump clicks off varying from pump to pump if you use that as the reference stop, and a few other issues. The way to minimize those errors (note minimize, not eliminate) is to use a larger sampling - i.e., take many tankfulls to do the calc instead of just a few.

 

What setting on the H/S gives you your best mileage? I seem to get the best mileage with the H/S on stock setting.

I have a Mega Dually and I have the california style delete I am averaging 14.8 just driving this is with 75/80 on interstate and small trips around the ranch. Best I have got so far was just under 19 all highway driving.

My truck was broke in pulling gooseneck was installed at 25 miles never went down the road without a trailer until just over 7000 miles. Around 3000 miles the engine really woke up hills that I needed to shift into 4th gear I could now pull in 5th.

 

Not to mention the inaccuracy of the odometer to begin with. I fuel up at the same pump and try to keep the variables down, but it is all just an approximation. Even a 10 degree swing in the ambient air temp will change the diameter of your tires a bit...

 

I got my 2010 about two weeks ago. The first two tanks showed 13.5 and 15.5 on the computer, both were 15.00 hand calculated. (both combined city with mostly hwy)
The third tank was 11.4 and the computer showed 11.5 This tank had a lot of pulling 13,000 lb load in it.

I have to say that my 2007 5.9 dually never did this good ever. The best I ever got running empty was less than 15. Pulling it would drop down to 10 or less. I am happy with the new rig so far, and the 6 sp tranny is a big improvement over the 4 speed.

I unplugged the EGR valave so we will see if it actually improves the MPG.