That's pretty horrible haha my old truck has the 8.1L Vortec with the Allison. Great truck but it loves the fuel!
Temperature, Pressure, and Vapor Expansion in the tank play a large role in its calculations, and it’s still just an estimated calculation. They might perfect them someday, but they’re only marginally accurate at best in most cars now, mine is usually .5 low to 2 highHave you guys found your in dash fuel MPG gizmo to be very, very generous? I wish I was actually getting the MPG that thing claims I am. I call it the lie-o-meter at this point. Thing is 3-5 MPG off, especially when towing. When empty it is closer...but still not accurate.