[Dantilla]

It's purchase price was much higher than the standard Mooney, and it offered no better performance. Thus, not many were sold. Its big advantage was a single power lever, instead of the three (throttle, propeller, mixture) used in most airplanes.

The downside was excessive cooling drag. Using a fan just like the car was supposed to keep the engine temps more stable than simply using airspeed over the cylinders. The air exiting the engine compartment was so turbulent under the belly that the Porsche powered Mooneys didn't have inboard gear doors. It was determined that they would not increase speed, they would just add weight and complexity, so they were eliminated.

I remember hearing that some Mooney engineers were frustrated at the Porsche engineers, because they would not listen about their concerns- The Porsche engineers thought they knew all there is to know about air-cooled engines, and ignored any discussions about cooling drag.