Unless a large-scale war breaks out in the middle east, cutting off oil supply, we'll never see high performance diesel engines.
Car manufacturers will not invest R&D and manufacturing money into car engines that sell at a glacially slow pace and into engines which can not run on fuels currently available to consumers.
The oil & gas companies will never invest the millions, even billions it would cost to clean up diesel to Euro specs, given that it accounts for a very, very small slice of their profit pie.
It's a vicious circle, where low demand for the cars keeps demand low for diesel. It would take perhaps literally earth shattering changes to occur in the global economy before we saw a Ford Taurus TDL 5-spd capable of 130 mph, 50 MPG, and 0-60 times of under 9 seconds.
