Audi R8 V12 TDI Production Model Development Halted

After nearly a year of internal debate, Audi has officially decided not to produce the highly acclaimed R8 V12 TDI concept.
According to AutoExpress who spoke with a "high level" Audi
official, the cost of modifying the R8 to accommodate the massive
6.0-liter V12 TDI engine was simply too high for them to recoup through
the limited sales this model would have produced. The issue was further
complicated by the fact that diesel sales in the US are nothing short
of dismal, making the V12 TDI a hard sell considering that the US
accounts for nearly a third of all R8's sold.
When it first appeared at the 2008 North American International Auto
Show in Detroit, the R8 V12 TDI concept stunned onlookers with its
aggressive styling and insane performance. Powered by the
aforementioned 6.0-liter V12 TDI engine, the concept boasted 500
horsepower and 1000 Nm of torque which allowed it to run from 0 - 100
km/h in 4.2 seconds before hitting a top speed in excess of 300 km/h
(186.4 mph).

Source: autoexpress.co.uk