[stiletto2]

Go-Ped maybe? You should also be a little more specific on intended use. Of course the Go-Ped is not acceptable for other than 25 mph speed limit neighborhood roads. Most 50cc scooters are not much better than that either.

Without modifications, and still be practical for most roads except not freeways, the 125cc to 200cc class would be where to start looking. Honda PCX 150 owners get close to the magical 100 mpg mark. The Honda PCX 125 is in the realm of that 100 + mpg. But again, there are variables like road conditions and the inclines to overcome, wind, rider weight, stop & go traffic and riding style that will all have an affect on fuel economy.

Then again, there are electric scooters that might do better in a mpg equivalent way, but are limited in range. Probably speed limited as well but that would be just my guess since honestly I know little to nothing of the electric scooters.