The Bentley 6.75-liter V8 engine dates all the way back to the 1960s where it originated from Rolls-Royce, but it would appear this powerful engine's days are numbered. Car and Driver recently had the chance to talk to Wolfgang Dürheimer, Bugatti and Bentley CEO, who discussed the future of the Bentley brand ahead of his imminent departure to Audi. He confirmed that the Volkswagen-owned ultra-luxury brand will be phasing out this engine in favor of more efficient diesels and plug-in hybrid powertrains.

Based on the C/D article, the diesel engine will first appear as an option in Bentley's first-ever and forthcoming SUV – the EXP 9 F pictured above – and then it will trickle down into the sedans. No official word as to which diesel engine will be found under the hood of future Bentley vehicles, but C/D thinks that it will be a new 400-horsepower V8 TDI engine expected to launch next year in the Audi A8.

A diesel-powered Bentley isn't as big of a stretch as you might think. After all, Dürheimer played a critical role in getting diesel engines into the Cayenne when he was the development chief at Porsche.

In other news, Dürheimer also talked about the future of Bentley in regards to plug-in hybrid technology. PHEV isn't a totally new idea to Bentley – it was mentioned when the EXP 9 F Concept debuted earlier this year – but the interesting note here is that Dürheimer confirms that the plug-in powertrain will be available on other models, as well.