Ricardo Inc., which provides engineering services to the auto industry, says it has developed a new flex-fuel engine technology combining direct injection and turbocharging to narrow the fuel-efficiency penalty of ethanol.

Ricardo President Dean Harlow expects the technology, called Ethanol Boosted Direct Injection, to stimulate demand for ethanol fuel when it comes to market from an OEM as anticipated in roughly three years.

“EBDI is for people who are not just green-oriented, but people who are watching their pocketbook,” Harlow says during a sneak preview of the technology. Ricardo unveiled the technology recently at the Society of Automotive Engineers' Government/Industry Meeting in Washington.

Several auto makers, most notably General Motors Corp., consider alternative fuels, such as E85, the most significant near-term solution to offsetting rising demand for vehicle fuel and reducing greenhouse-gas emissions.

GM estimates sustainable biofuels from next-generation, non-grain cellulosic sources could offset vehicle energy demand 35% by 2030.

In many parts of the country, E85, a blend of 85% ethanol and 15% gasoline, costs as much as $0.30 per gallon less than gasoline. In other areas further from ethanol refineries, where E85 pumps are less plentiful, the price remains competitive.

But a current flex-fuel engine using E85 suffers a 30% penalty in fuel-economy, because E85 contains less energy than gasoline, making it a more expensive alternative.

Ricardo thinks it has solved that problem by taking advantage of the higher octane rating and higher heat of vaporization inherent to ethanol.

Those characteristics allow the company to use a high level of turbocharging to achieve the high cylinder pressures ethanol enables, says Rod Beazely, director-Gasoline Product Group at Ricardo. The result is a spark-ignited, flex-fuel engine with performance capabilities near those of a diesel engine.

“We think we have a breakthrough,” Beazley says.

In addition to direct injection and turbocharging, Ricardo's EBDI engine also uses variable valve timing, optimized ignition and advanced exhaust-gas recirculation.

So far, Ricardo has closed the efficiency gap between ethanol and gasoline to “around 20%,” its engineers say.

That work was done using a 3.6L DIG engine rigged for flex-fuel use, but the company soon will apply its technology to the 3.2L V-6 engine of a dual-wheel, demonstration pickup. The 3.2L mill illustrates the “extreme-downsizing” capability of EBDI, Ricardo says, as it would serve as a replacement for larger gasoline or turbodiesel engines in the 8,000-lb. (3,628-kg) truck, while still providing enough power to tow a 4,088-lb. (1,854-kg) trailer up a 20% grade.

When running on ethanol, the company expects the 3.2L to deliver peak power of more than 450 hp and 663 lb.-ft. (700 Nm) of torque at 3,000 rpm. With gasoline, the performance figures degrade to an anticipated 405 hp and 571 lb.-ft. (775 Nm) of torque at 3,000 rpm.

Ricardo says the engine technology is scalable, with applications ranging from small cars to medium-duty trucks, and its time-to-market will coincide nicely with the expected arrival of next-generation cellulosic ethanol.

Development partners include Behr GmbH & Co., Robert Bosch GmbH, Delphi Corp., Federal Mogul Corp., GW Castings Ltd., GM and Honeywell.

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