Diamond really pins its future on diesel. I hope they fix the Thieler design problems with this one; too many ADs to make it owner easy. A Diamond diesel was at my airport last week; very interesting sound. Looked like a twin motor glider taking off; no rocket ship but graceful.
Diamond is the aircraft manufacturer (Super dimona, Katana, DA20,40,42,50, D-jet). Thielert certified a modded Mercedes-diesel and Diamond put those in their aircraft, first the 1.7, later the 2.0. They had major problems with the gearboxes, Thielert burst and many owners were pissed. Thielert Centurion - Wikipedia, the free encyclopedia
Austro, a wholly different company "evolved" the original Thielert in a more powerful engine, the AE300 and claim it's much better, but the future'll (dis)prove that. Austro is owned (right?) by Diamond and a long-time engine manufacturer, notably by their Wankels. Austro Engine E4 - Wikipedia, the free encyclopedia