Comment 17 for bug 159066

Ok thought about it further, and I think I have found the "magic" formula;)
The calculation is only correct if you do full refuels, as said before. But if you do partial fills it gets confused. So we need something to indicate its not a full refuel.
With this in place you can summarize all partial refills and add it up to the next full refill and calculate with this.

e.g.
you do 3 partial refills and then a full refill
so you driven the distance from the last refill and the 3 partial refills before.
same for the gasvolume: volumefullrefuel + 3 partialrefillvolumes
with this then: totalfuel * 100 / totaldistance

(I hope you understand as I'm not a native speaker)

What do you think?