I shall have the dissenting voice then....
They're heinously outdated pieces of equipment.
160HP-180HP out of 360 cubic inches? That is as bad as a late 70-ies Corvette.
4 pistons the size of saucers running 2300rpm?
40l/hr at 120kts? That's 18.3 l/100km...atrocious.
My claim to fame?
Non stop flight from just outside Boston to Naples, FL in a DA-42 Twinstar with 65 gallons used. 250 liters for 2200km for 11.4l/100km in a twin engine aircraft.
I've always liked the 1.7L more then the 2.0L Thielert.
In any case these engines are the Mark 1.0..lots of room for improvement still.
But for fuel consumption and noise levels...wow.
http://www.pprune.org/private-flying...flights-2.html