There’s a new flagship Bentley sedan in town and it’s called the Mulsanne, named after the famous straightaway in the 24 Hours of Le Mans. It was unveiled at the Pebble Beach Concours d’Elegence in Monterey, California today. It replaces the Bentley Arnage and is a completely unique platform. The Mulsanne doesn’t share any parts with other Bentleys or Volkswagens, and it’s the first Bentley since 1930 to be designed completely by the company’s in house engineers. Bentley says the Mulsanne is the ”pinnacle of British luxury motoring”, so hit the jump for the rest. [Source: Bentley]

Not too many technical details have been released but we do have a set of pictures of the exterior. While the taillights are distinctively Bentley, the rest of the rear end might remind many fans of the Rolls Royce Phantom, one of its direct competitors.

It’ll most likely be powered by a reworked version of their 6.75-liter twin turbocharged V8 engine from the Arnage. The big V8 will be capable of producing around 500 horsepower and 740 lb-ft of torque. Of course, Bentley is not above the green car movement and assures us that they have reduced the emissions as much as they can by using lightweight engine parts. There’s also some buzz about possibly including a cylinder deactivation system. The final emissions cut: 20 percent. Just like their other new car, the Bentley Continental Supersports, owners of the Mulsanne will have the option of running the car on E85. No performance figures for E85 fuel have been released yet.

They’ll be showing off the Mulsanne at the Frankfurt Motor Show and probably giving the exact specs and pricing. Expect this big sedan to hit the streets in mid 2010.