A novel clean-burning engine combines gas and diesel fuel on the fly by blending the two within the combustion chamber.
Tests by a University of Wisconsin-Madison engine research group headed by Rolf Reitz show a diesel engine powered by a gasolene-diesel combo produces significantly lower pollutant emissions than conventional engines, with an average of 20% greater fuel efficiency as well. These dramatic results came from a novel technique Reitz describes as “fast-response fuel blending,” in which an engine’s fuel injection is programmed to produce the optimal gasoline-diesel mix based on real-time operating conditions.
Under heavy-load operating conditions for a diesel truck, the fuel mix in Reitz’ fueling strategy might be as high as 85% gasoline to 15% diesel; under lighter loads, the percentage of diesel would increase to a roughly 50-50 mix. Normally this type of blend wouldn’t ignite in a diesel engine, because gasoline is less reactive than diesel and burns less easily. But in Reitz’ strategy, just the right amount of diesel fuel injections provide the kick-start for ignition.
