Doug,
   Just last weekend I spent a couple of hours talking with a turbo mechanic,
   he's building a RV9- very similar to the Vision. He was telling me about a
   turbo one man can hold with both hands which can be used in a light
   aircraft, didn't mention hp but said one was used in an RV in the States,
   but like you said fuel burn is double and the cost would be something like
   $100,000 - but he said the cost was coming down.
   Personally I think a larger fuel capacity carrying plane would better served
   with a turbo prop as I believe cost of development would be comparable to a
   turbo prop installation , which only leave fuel burn the only remaining
   factor.
   One could run 3, 13B motors.
   George (down under)



You can run 3 engines, one on the tail and two on the wings. All the
plumbing through one big radiator.

Dan