When you heard that Bentley was considering adding hybrid powertrains to its line, you might have been left thinking: small electric motor adding a couple mpgs to a callous, CO2-spitting W-12 or V-8 engine.

Maybe they'll actually break 20 mpg highway. Maybe.

Turns out, though, Bentley is planning to go full-on plug-in hybrid and may make a more meaningful dent on its abysmal ratings.

Bentley/Bugatti chief and former Porsche exec Wolfgang Dürheimer has been doing a whole lot of talking to print and Web journalists lately, and we've been learning a whole lot about the future at VW's most luxurious brands as a result. This time, Dürheimer expanded upon his views of the role that greener powertrains will play in Crewe when speaking to Car and Driver.

Right now the greenest thing in Bentley's stables is the bio-fuel capability of the 2011 Continental GT and recently detailed 2012 Continental GTC. But Dürheimer expressed some reservations about bio-fuel, stating that he's not satisfied with the capabilities of E85. It looks like Bentley may abandon bio-fuels for greener pastures in the future.

It seems that some sort of hybrid powertrain will be at the crux of Bentley's future eco-conscious design. Dürheimer said of the move: "We will jump over the first generation of hybrids and start with the plug-in hybrids."

When asked how much all-electric driving we can expect from a plug-in Bentley, he said he's thinking along the lines of 16 to 19 miles. Bentley will take advantage of its membership in Volkswagen AG, borrowing some of the group's technology in developing its own hybrid.

While Bentley may offer a plug-in option in the future, it will in no way abandon the big W-12 responsible for such numbers as the Continental Flying Spur's EPA-worst 11/18 mpgs. Bentley will start offering a V-8 option on the Continental GT early next year, but it has no plans of phasing the 12-cylinder out. Dürheimer expressed strong support of the powerplant, stressing that it helps to set Bentley apart from the competition.

As for diesels, Durheimer reiterated the possibility, saying: "If the new-generation diesels make no smoke, no noise, this matches perfectly with the demands of a Bentley, so why shouldn’t we take it?"

[Car and Driver]