Ugly and probably has not power to speak of. Does it get 5 or 6 mph?
I first wondered how many miles per gallon it gets. Then, realizing that was a ridiculous question because I don't believe we know what the alternate fuel may be (could be cords of wood/km), I thought about miles/cubic foot of air.
But it more probaby is something like feet/cubic feet. Dimensionally, this would be 1/ft2. Improbable.
Then I thought, To heck with it. My kids already have a golf cart.