[newnewpdro]

I highly doubt your fz1 got 50mpg while traveling over 120mph.

Presumably you mean you averaged 50mpg across a tank of gas which included some time spent > 120mph, which is a huge difference. Most riders can't really sustain > 120mph for an entire tank of gas, which is typically the granularity of measurement for casual mpg estimates made at fillup time.

My experience with liter bikes was that the fuel economy dropped to < 10mpg approaching vmax, which in combination with their small tank capacity poses a very real problem for those fleeing police.