For an equal amount of HP, the fuel consumption is surely less on a Rotax?
Power comes from burning fuel. Once you are running stochiometric, that's your lot. Physics is physics.
The ignition system I described above has less bits than traditional mags. The oil system has no pumps, it operates off crankcase pressure. I think all in all, parts are about equal.
However, total magneto failures are not statistically significant. Oil pumps do get shredded sometimes; that's true, but usually only after something else got shredded first...
Also the very few gearbox failures on the 900 series engines were operator induced
You could say that about most engine failures
Quite interesting. Do you have a link?
It was in Usenet, about 10 years ago. Some SFC data was posted by a car engine designer. However, I have been recently told by GAMI that the old engines beat every car engine, and they should know.
Most of the R&D that goes into car engines is to give good MPG and low emissions when running at low power.