Gasoline-Fueled Diesel Truck Engine Cuts Fuel Use, Emissions

How do you make a diesel engine more efficient? One answer may surprise you: Run it on gasoline.

That's what researchers at Sweden's Lund University are doing, and they believe this combination could cut both fuel use and emissions in heavy-duty trucks.

Lund's experimental engine uses a different combustion process, called Partially Premixed Combustion (PPC), which researchers say could increase a large truck's fuel efficiency by 50 percent.

This process uses two fuel injections for each combustion, the ratio of which can be changed to alter the behavior of the combustion.

This in turn allows for control of ignition delay--the time between fuel injection and combustion--which ensures that fuel is burned more efficiently.

According to Bengt Johnasson, a Lund professor specializing in combustion engines, the process significantly reduces particulate and NOx emissions, to the point that a production engine might not even require a catalytic converter.

The current test engine operates at 50 percent efficiency, compared to around 40 percent for standard diesel engines.