I think it's based on the geo 3 cylinder. I'd have to check again, but I know it's in the public domain.
Well, it's quite a reasonable engine for a target weight of 570 kg (1,250 lb), but with that weight I doubt it will go by as a motorcycle in any jusrsdiction, or will it, in the US?
Also, stated fuel efficiency happens to be 84 mpg-US highway, but only 60 mpg-US EPA blended, which is good, but not that surprising.
What is surprising though, is how did they managed to achieve great safety rating?
The US federal definition of a motorcycle is basically anything you can drive that has less than four wheels.