Should Audi build high-performance "S" diesels?

Could a "DS" range of Audis meet the needs of performance nuts and greenies? Columnist George Achorn seems to think so. He says Volkswagen and Audi already have a wide range of high-powered diesels that could take the place of regular gasoline engines in the company's sports cars. "Think of the S4 as it is now. However, drop Audi's new chain-driven 4.2 TDI under the hood and badge it the DS4," writes Achorn. "The car would look and handle like the current S4, and we know by seeing the performance of the A8 4.2 TDI that performance wouldn't be far off of the petrol S version. Even better, the larger and heavier A8 4.2 TDI gets 30 mpg, well above the S4's North American rating of 21 mpg." He further suggests a DS6 and DS8 would also be possible. "It wouldn't be that tough. Even we Americans know the prowess of the V10 TDI fitted in the Volkswagen Touareg. Package that engine in the body of a new S8 or S6 and you'd again have a very interesting pair that would perform not far from the S version at a fraction of the fuel consumption."