Duramax vs Power Stroke Fuel Economy Tow Test and Drag Race

The computer displayed mpg was almost exactly accurate on my 2011 Powerstroke. My 2016 lied and it was not always consistant in how much it lied by. Generally hand calculated proved to be about 8% better than the computer said. I used to check every tank but can't remember checking my 2017. I no longer fill with at a metered pump.