not new news but:
Citroen C5 2.2 twin turbo diesel, first in-line 4 diesel to have two turbos:
http://www.whatcar.com/news-article.aspx?NA=220817
the Mercedes concept: triturbo:
http://seriouswheels.com/cars/top-20...LK-320-CDI.htm
also consider the well known BMW 535d
http://www.pistonheads.com/doc.asp?c=100&i=9847
there is a real push in diesel technology, it started with high pressure injecotrs, common rail and now its also affected turbos, we had vtg (variable turbine geometry) and now we get more turbos for low and high end boost. where to next? Has anyone else got any opinion, examples of this phenomenon. Why do main stream petrol engines not have this much attention?