As a result, the engine is able to close the gap between spark-ignited engines and diesel, says Cruff. "We can get equivalent performance out of the vehicle and, in some drive cycles, equivalent fuel consumption," adds Beazley. Besides boosting the performance of ethanol-gasoline blends, these modifications also deliver improvements with gasoline, although the benefits aren't as great. The turbocharging, for example, allows the use of smaller, more efficient engines without sacrificing power.

This is a natural progression, says Hua Zhao, director of Centre for Advanced Powertrain and Fuels Research at Brunel University, in London, U.K. "Various companies are trying similar approaches," he says. "It's a good idea, and part of a trend to downsize engines by replacing big engines with smaller ones."

The technology is different from another approach to boosting engine performance with ethanol. In that approach, the engine is optimized to run on ethanol, and when gasoline is used, small amounts of ethanol are injected from a separate fuel tank into the engine to prevent knocking. (See "The Incredible Shrinking Engine.")

Currently, Ricardo's concept engine has only been tested under laboratory conditions. But the company is installing a prototype in a GMC Sierra 3500 HD pickup truck. By replacing the large 6.6-liter, V8 diesel engine with Ricardo's smaller 3.2-liter, V6 EBDI engine, it should be possible to get the same sort of fuel economy and performance from the vehicle. The technology is also very scalable, says Beazley. Besides replacing engines in passenger cars, it can be used for engines in large agricultural equipment, he says.