I'd go for 100mpg if cooling and materials are strong enough.
I think 72mpg on 1 cylinder, 1 passenger...and drop this thought to 40mpg, not even 50% less, and think, 10 gears, AWD, 3000 pounds and 5 passengers and a spare 1781cc in the back towing a trailer up to 100 scooters heavy...
See? I am not scooter worthy. It is still a selfish machine.
That is decent to have a machine that can do the 70mpg however.