Well I just got home from san fran ca where I purchased my 2nd 6.0. I bought my first one new. This one is also a 06 6.0 but a lot nicer. The last truck was a dually with 4.10's and if I drove with traffic I would be doing good to get 14 (hwy). However I could run at 55 without cruise and have gotten 19 (once). This drive by wire takes a feel to make sure we are not giving too much pedal, and when we are not giving enough. I didn't read all the bickering about who keeps better track, and how, but I can say that I have enough info on my old truck (400k worth of history) to keep track of when things are not right. I would like my name in the hat about who is the most cumpulsive about calculating milege. But I drive this truck for a living. I would check my milege with the fuel receipts and the gps. I have gotten very familiar with my truck and when things are not right. This new truck just blows me away, I just ran about 2000 miles in the SRW (with about 250 in very busy LA CA) and I figured total trip and each tank at every stop. My garmin allows me to have multiple trip odometers. I got as high as 20.4 on the interstate running 63-64 (with no cruise) and the total trip I got 19.3. The mpg guage only went as high as 18.8(that was with me not resetting it throughout the entire trip). I figured I would just throw in my info.