On my truck i got up to 22mpg due to being in 6th gear and cruising around 60mph.. (took back roads to a party that was about a 2 hr drive.) the deletes i had done at the time was the dpf, and k&n intake, and edge tuner..

My cousins 09, 6 speed, 2wd, stocker is still getting 16.5 hand calculated driving like a grandpa:td:

I never trust my overheads. The one in my 2000 is usually 1-2 miles off of what Im actually getting. My 07 is everywhere though :scare2: I never even look at it. My 07 gets 19-21 hand calculated. :c:

I'm on 40's and 4.56s and the other mods in my sig, and My overhead never goes below 17mpg, Hand calculated I'm around 15mpg average. When I moved last september, I drove 1200 miles most of which I drove around 75mph, and was between 15-16mpg, hand calculated, the entire trip. When I had 37's I was averaging 19mpg, and the overhead would be around 21-22mpg. My overhead is usually around 2mpg higher than my hand calculations.

Did you ever get the ECM reprogrammed for tire size when changing tires?

I use the mini maxx to recalibrate for tire size and double check it with a GPS to make sure my speed is correct.

Just bought an '07.5, 6.7. 13 mpg on first tank. Whew! Help!how do I get to 20 mpg and how much will that cost?

Fuel Mileage
 

Good luck with 20. If its a 4x4 or a dually you'll be lucky to get 18. I get 16 to 17 on a regular basis, but that's about it. If you wanna get CLOSE to 20, get a Smarty or H&S tuner, straight turbo back exhaust and that's it. Some people say get a cold air intake too, but I've heard bad things, like lower MPG, unless you're pushing 600+ HP. If you need a how-to for installation, there's carbonitecummins.com for complete instructions. Happy Truckin':choochoo:

24 witnessed by others
 

Stock tires, nothing big, no load in truck, good tune up, H$S black maxx, route Utah border to Denver over I-70. Over and Back. No big accelerations, smooth transitions. two guys with me, 24mpg round trip, no trailer. All Amsoil lubricants. miles on truck approx., 25000. Bigger tires, lift kit, maxx tuner, tool box in the back, two smaller guys, same route mileage ran 18 round trip.

i get 22-23 on the overhead around my home in wv. i have hand fig and its about 1 mpg high. i have saw 25-26 on the overhead on a long trip to gatlinburg tenn. i have stock tires. afe cai, and a smarty. i also run royal purple and amsoil oil. i have saw several trucks vary pretty bad.:hellox: