Will Audi build the world's first diesel supercar?

Will the Audi R8 supercar have a diesel engine similar to the one used in the R10 race car? In a recent column on Fourtitude, columnist George Achorn speculated that Audi could use a V8, V10, or V12 diesel. In December, Audi unveiled the R10 race car with a 650 hp 5.5-liter V12 diesel. Achorn reports that the spy photographers recently spotted a Lamborghini Gallardo test mule that sounded more like a diesel than a regular Gallardo. The Audi R8 rides on the Gallardo platform. (See also: recent spy shots).