Amazing mpg on my stock truck..
 

Over a span of the first 6,500 miles I have averaged 21.6mpg. Half of this mileage towing 12,000lbs. I'm more than impressed with these results. I can only imagine the possibilities if I could remove the emissions controls that waste fuel..

What are you basing your mileage on, hand calculations, or the over head lie-o-meter?

Hand calculation. I also use the cruise control as much as possible. The computer is always pretty close to the manual calculation however.

That seems to be a bit generous, especially with only 6500 miles on the engine, and all emissions trash still hooked up. :nope:The engine is far from being broken in at this point. Fuel mileage will get better as the engine gradually breaks in. The skeptic in me is rearing its ugly head.:humm:

does sound a bit over the top. I average 16.5 mega cab dually 4x4

Ive heard that really good fuel mileage can be had from a 6.7 cummins with all of the available deletes for that engine. Seems like a hell of a lot of work to do to get it, and pricey.

You don't say if truck is 2wd or 4x4.
I find it hard to believe if truck is 4x4.

Stock 2012 Cummins, 4x4, Crew Cab - 20.1 MPG
 

Here is a sample of the MPG I received after they flashed my computer with the latest EPA patch... I asked them NOT to do this and someone screw up and did it anyways at the dealership. Note, I am getting 12-13 MPG in city. I am having problems uploading my picture thought it shows 20.1 MPG.

I can't get those MPG with my 2008 F-250 2WD with dpf deletes:nope:

Maybe down hill, with a strong tailwind.....:w2: