Bentley is well under way with a plan to replace the mighty Arnage in 2010. It’s a project that will require the Volkswagen-owned company to address green issues, but will also provide the basis for a new generation of Bentley models for the next decade.The new car is likely to be built around an aluminium spaceframe chassis made by Audi, skinned with aluminium panels. A major reworking of the factory — in preparation for other future models — could also be part of the Arnage project.Although the car should be powered by Bentley’s venerable 6.75-litre V8, this is likely to be hooked up to a hybrid drivetrain, using either major components from Audi’s new-generation quattro hybrid running gear, or the hybrid transmission already being developed for the Q7. In a recent interview, Audi engineering boss Michael Dick said all the new Bentleys would use a version of Audi’s spaceframe, cutting around 150kg from the bare bodyshell.The Bentleys will use the core of the Audi structure, which will be available in three different sizes, but with new metal from the waistline upwards. For the Arnage the base of the windscreen will be mounted higher and the pillars reshaped. Bentley says the first evidence of its new, more environmentally friendly thinking will be seen at the 2008 Geneva motor show.In a candid interview with Autocar, Bentley boss Franz-Josef Paefgen revealed that he regarded the Arnage project as the biggest challenge for Bentley since the 1930s.“This will be a totally independent car,” he said. “It will not be like the Continental, a derivative of a VW Group product, although it will use components from the group.”Paefgen also stated his determination to keep the classic 6.75-litre V8 alive. Despite the fact that the engine turns 50 in 2009, Bentley wants it to pass new emissions regulations.“Meeting the 2009 EU5 emissions limits with this V8 can be done,” he said. “We are now working on the proposed EU6 limits for 2013-15. All our engineers want to keep the engine alive.”Paefgen also admitted the company now had to face green issues. “We are looking at a long-term problem that will develop over decades and centuries,” he said. “If we have to reduce fuel consumption by 20 per cent, we will do it. But we have to satisfy our customers and build a proper Bentley.”Autocar understands that the idea of building lighter, smaller cars with downsized engines has been discussed. However, Paefgen hinted that this option had already been dumped. “We may need to shed weight, but we still need to produce cars of a Bentley size,” he said.