Dar, those are interesting points. It all depends what business you're in. A 60 MPG Honda Insight isn't a good choice for a cargo carrier like UPS even though it is economical. Just as much as a 10MPG Freightliner cargo hauler isn't a good choice for hauling groceries even though there is plenty of room inside.

I like this wiki page:

http://en.wikipedia.org/wiki/Fuel_ef...transportation

In particular the 653MPG they claim for a a human on a bicycle.

That brings up an another thought. I recently saw a crop duster in our area spraying fields. it wasn't what I expected because it was a helicopter. I don't know how the books work out on that but maintaining a heli isn't exactly cheap. My first thought was how does he make money?