I fall in your category of not reliable fuel verification. I do calculate fuel mpg from fill up gal and miles when I refuel but I have “only” 33K miles in nearly 2 years, so I guess I don’t count. I do have a lifetime average of 25.96 mpg and have never had one tank of less than 24 so my mileage is better than yours but since I don’t use your app I know my results can be disregarded.
I have noticed I get considerably better fuel mileage when I don’t use the cruise control. For repeat trips I have recorded 2+mpg better with it off. Too many other factors can affect mileage to defend that, fact wise, so I don’t make much of it. If I wanted to get 23.7 perhaps I could if I ran 75-80 mph, with cruise on and a 1,000 lbs. more in the van. However if those with gassers did the same I doubt they would be getting 17mpg and the diesel would still get 140% or better fuel mileage. This is my real point here. This diesel gets MUCH better fuel mileage than the gas engine and it needs to as it cost more to buy and the fuel is generally more.
My 500K lifetime for the ENGINE was related to this engine in high mileage Cantors not in this van as probably no one has gone that far.
Hey it could be worse. Kip is on his THIRD engine in one of his gassers! Would that be better?