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.
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