Greener dream a Spur for Bentley

A greener ethanol engine is one way Bentley plans to protect its place at the top of global motoring.

The luxury British brand will slash exhaust emissions and boost fuel economy under sweeping plans under development by Bentley in partnership with Volkswagen.

It plans to suck the engineering expertise of its German parent company and then adapt VW technology to its own range.

The plan is firm, but Bentley head of engineering Paul Jones is not big on detail.

Speaking at the launch of its 2009 Continental Flying Spur models in Boston, Jones hints that Bentley will take a series of stabs into the heart of its range's high fuel consumption.

He indicates the first move will be biofuel-compatible engines in an effort to get the brand's CO2 emission levels down towards the proposed European Union's 120g/km target.

So engines with Saab-style E85 compatibility will become available within two years for the US and Europe. There is nothing firm for Australia as the rollout of E85 fuel is still in its infancy.

Jones says Bentley will not be party to sourcing ethanol from human feedstock.

“We will not become involved in using food crops to power our cars. The E85 fuel will have to come from other sources such as wood pulp and the woody stalks of crops,” he says.

The first Bentley to get E85 compatibility will be the Arnage V8. This 50-year-old engine is expected to remain behind a Bentley badge for at least four years . . . perhaps longer if it can meet future emission regulations, says Jones.

But it is expected to be replaced with a new powerplant by 2012 which he hints “will have a 40 per cent reduction in CO2”, and therefore, a 40 per cent decrease in fuel consumption.

“But it will have no change in performance. We won't do business if we have to reduce performance. Our customers have very stringent demands,” he says.

Jones will not indicate what powerplant will make these reductions, though his hints arrive around the same time the Volkswagen Group — including VW's major shareholder Porsche — has outlined a new push into hybrids.

Bentley has suggested it will make its cars lighter to help the fuel economy which, in the 2.5-tonne Flying Spur saloon, averages about 17 litres/100km.

A fuel-efficient Volkswagen DSG semi-automated transmission is possible, but Jones says the W12 engine's high torque will be too high.

Other than the hybrid route, Bentley also has access to the Volkswagen turbodiesel engine range including a bi-turbo V12 and V10 it has developed for its Q7 four-wheel drive and R8 supercar.