Scooters main priority have been cheap practicality. Fuel efficiency is part of the “cheap” part.

Yamaha’s blue core engine used in its mid sized 300cc scooters can do 2.8L per 100km. It’s 125 engines can do 1.8L per 100km.

They’re incredibly efficient little vehicles

So far electric scooters can only compete in inner city with the equivalent power of a small 125 and limited range/speed due to size/weight constraints