[jccooper]

There is a brief mention of efficiency, but that doesn't seem to be a big point. The port structure does make me think it might be a bit dirty--kinda two-stroke-y.

But not all engines go in cars. Might be a nice one for aviation--though aviation engines are maybe even more handicapped against change than those in automobiles. The experimental aircraft market ain't that big. Other markets where Rotax lives might like it; pumps and such.

Anyway, that's probably another one of the reasons they're not expecting automotive applications in the first generation.