Yeah, you're probably right, but you'll also probably agree that lighter weights = more revs =
more fuel. I don't doubt the change in performance for the better.. but I doubt the MPG
figures have anything to do with the change, probably just rode a bit slower that last tank.
I went from 14g to 13g weights (standard, not pulleys) which improved the acceleration
a lot, but the top speed went down from about 70 to 60mph, and MPG figures went down
by 20%, more or less.
I've got 6k miles on the 14g weights, and maybe 3k miles on the 13g now and have checked
my fuel consumption probably 50+ times.. Easy throttle inputs and speeds up to 40mph result
in about the same consumption, but anything over that, the revs go up significantly and so
does the consumption.