Herr Starr, I'd have already made this sheet if Teresa had any instant FE display, because I'm very interested. Filling up is quite inaccurate though, I just can't fill to the exact same point. I even use the distance between low fuel light instead of the fillups because of this, but I suspect that the fuel level sensor isn't accurate either
This inaccuracy can be attenuated by long distance tests, but who wants to do the same test over and over, for several thousand kms? And wouldn't that be a total waste?
So I won't ever had 'clean' data without the strong noise of everyday use. Temperature, wind(!!!), rain, traffic conditions are going to distort my data, no matter what.
In my case speed dependence is an even trickier factor, because I can't shift into 5th before reaching ~70km/h (43.5mph), and even 4th begins at ~50km/f (31mph) so it probably isn't a smooth curve at all.
All I can say about it that 4th is probably somewhat more efficient than 5th if I go at its bottom, I've tested it this winter when I was cold at higher speeds
I don't have any usable numbers on it, though. My worst solo tank was 3.23l/100km (72.8mpg) this winter, but I can't really compare. I rode in colder weather than a year before, and I rode much more (the winter before the tank I filled at the end of December lasted till 20th of March, this year I had 5 fillups in that time interval. Probably because of the less snow.)
Weight? I ride both 1-up and 2-up, and I can say that an additional ~160lbs passenger makes FE worse by no more than ~10%. I can't be sure again, because of the lack of a scientific test.