"The main impact of e-fuels is on existing fleets, not in the regulation of new vehicles being hotly discussed in Europe," Zipse said.

"We aren't discussing the existing fleet. The only opportunity to make a difference there is e-fuels. I agree strongly with the colleagues proposing that, particularly because our motors are prepared for it," he added.

Oliver Blume, chief executive of Porsche and Volkswagen,, lobbied strongly in the annual press conferences of both companies earlier this week for being open to using e-fuels, calling on politicians to incentivise their production.

(Reporting by Victoria Waldersee; Editing by Miranda Murray)