[Patrick]

Originally Posted by akumabito

For the engines, I am looking at these options: 125cc, 4spd semi-auto / 250cc, 5spd manual clutch / 250cc CVT -power output for all these engines would be in the 10 to 20Hp range, with the smaller displacement engine being on the lower side of that figure. Of these engines, which would be preferable?

Honda NX250: Honda NX250 - Wikipedia, the free encyclopedia

This one won the last Vetter Challenge @ 157 mpg with a relatively conventional motorcycle fairing: 2011 Mid Ohio Craig Vetter Fuel Economy Challenge results