Boyle,
Of course not, but that is not the point…with a Hummer you can go hardly 20 mpg. In fact you get 16 mpg ( http://www.fueleconomy.gov/Feg/noframes/22514.shtml ).
This is certainly not same reason as why the Piper has problems. It is the recession. But fact is that fuel economy has to get a lot better soon in order to cut down emissions and greenhouse gasses.
My ” papertiger ” ac in my blog gets mileage of 490 after 16 months of study ( not yet verifid by aeroengineers ).
Juke