Bentley, which uses up to 12-cylinder engines in its 2-tonne-plus top-end saloons, says the fuel slashes its CO2 footprint by up to 70 per cent. The luxury carmaker in 2008 started making its cars compatible with E85 (85 per cent ethanol and 15 per cent petrol - or any variation in between) as a means of reducing emissions and meeting proposed European exhaust gas regulations.
Bentley engineering director Dr Ulrich Eichhorn says even though E85 wasn't available in all markets, customers showed immense interest in towing a green line. "In markets where ethanol is available, we see high interest by customers,'' he says. "We estimate that from well to wheel - the lifecycle of the energy process - a Bentley running on sustainable E85 will have a whole of life CO2 reduction of more than 70 per cent.
"It makes a rational reason why a buyer would buy a Bentley. It promotes an environmental message. "We know of one customer who traded in an almost-new Flying Spur model and bought the latest Flying Spur with the E85-compatible engine.
"He did it for three reasons - environment, the fact that in Britain it saves him about $30 because of a lower tax; and his neighbour has a Prius and he is delighted that he can smuggly match its CO2 footprint. They may not be reasons chosen by most owners, but they make sense for him and there's a clear benefit to the environment.''
Bentley is facing a choice of going it alone with the proposed - and not yet legislated - 120g/km CO2 threshold of European delivery cars. It takes effect in January 2012 with a graduated introduction trough to 2015.
"We can either join with Volkswagen and take advantage of the lower emission level of the group's fleet, or go it alone. It's being discussed. Personally, I think it makes more sense to stay within the Volkswagen Group's fleet.''
Bentley last month proved the worth of its E85 commitment by settling a world ice speed record on the frozen Baltic Sea off the coast of Finland.
Former rally champion Juha Kankkunen sent a Bentley Continental GT at 330.69km/h over a 14km graded section of the 700mm-thick ice. The fuel used, says Eichhorn, was derived from waste straw.