Nope 60+ mpg is about what the turbo diesel suicide clown cars in Europe get. Not allowed in the USA, because of the EPA. No batteries needed.
Mopeds are even more efficient.
Me, living is far more important than MPG.
This thing won’t even be a speed bump for my Hummer. I love pulling up next to a Prius or similar “car” at a light and revving my engine. Counteracts all of their “green-ness” with one or two revs of my engine.