First Bentley made a promise in early 2009 to have its entire line E85 capable by 2012. Then it introduced its biofuel-compatible Continental Supersport not too much later; a car that could not only run on the environmentally friendly fuel but was also the fastest Continental in the Bentley line. With the unveiling of Bentley’s new Continental Supersports Convertible, the company has announced that its entire Continental range will be capable of running on regular petroleum, E85 bioethanol, or any combination of the two for 2011.
Currently most petroleum at the pump comes with a small amount of bioethanol mixed in, usually less than 10 percent. E85 fuel is 85 percent bioethanol (ethanol can also be produced via petroleum, the term bioethanol means it is only produced from organic materials) and 15 percent petroleum. The petroleum is only added to ensure that the car is cold-start capable.
E85 biofuel has a very high octane rating of 105 but a lower energy content that requires a 30 percent increase in the fuel-flow rate. This means Bentley had to do a complete review of the fuel system to identify and, if required, replace components deemed to be insufficiently resistant to the properties of ethanol. A sensor detects the blending ratio of E85 and petroleum and varies the engine mapping to ensure power, torque, and emissions remain at the same levels whatever fuel is used.