2006 Duramax Dually 4x4 pulling 25' Thunder - I get 14mpg - Delivered a 33' cross country to Havasu and averaged 12.1 including crossing the rockies. U should be able to average 11-12 I would think in an 07 Goat

I towed my 37 with a F350 Crew Cab Dually 4X4 with the 7.3L Powerstroke and got 11-12 running between 65-75. I had a Diablo 3 setting chip and ran it in the power (not performance) mode. Great truck for towing

With a gas motor pulling a 32, I would plan for 8-9 for stops and hope for 10-11.

The 6.7L is a Cummins diesel, not a gas burner. However, it's loaded with tons of new EPA crap to make it burn cleaner. Put it this way, I have 22k miles on it and the inside of the exhaust tip still looks brand new on a diesel. I'm all for being clean but it really cuts the mileage down.

I guess I have been lucky, I have not had one single problem with mine yet and like I said above, 22k miles and ticking. I looked at a 5.9 but just decided to try out the newer model with the exhaust brake and six speed auto tranny.

Did that wake that beast up??

The edge chip woke up my 03 7.3 power stroke on the lowest setting and i picked up 4 mpg in the process.