Best of both worlds
The University of Wisconsin has been working on what they call a Reactivity Controlled Compression Ignition engine. This system uses a port injector and a direct injector two introduce two fuels into the combustion chamber, such as gasoline and diesel (port and direct, respectively).
Gasoline engines are known for clean operation and high power. Diesel engines tend to have high torque and low fuel consumption.
Combining the two creates an engine that offers all these advantages in one package.
How it works
RCCI engines blend two fuels. Diesel is introduced into the combustion chamber through a direct injector. Gasoline (or alternatively methanol or natural gas) is sprayed into the intake with a port injector.
“By changing the injection timing and quantities of both fuels, optimal combustion can be achieved at many engine operating conditions,” Reed Hanson, Ph.D, Research Associate at the University of Wisconsin-Madison Engine Research Center (ERC), explained to Automotive Engineering.
The resulting engine is 20% more fuel efficient compared to a conventional diesel while at the same time meeting emission standards without the need for costly after treatment.
Should have seen it coming
The automotive industry has been inching up to this for a while.
Diesels have long used direct injection.
Gasoline engines first had throttle body injection, then port injection, then direct injection – each a step towards precise and timed introduction of fuel for better power and efficiency. Recent engines by Lexus have both port and direct injection.
Mazda’s SKYACTIV-X engine combines spark and compression ignition is a gasoline-only engine.
And now finally we have an engine that is a true hybrid of gasoline and diesel.
Can’t even be mad
I am an armchair gearhead and pay a lot of attention to what is happening with car technology, so when I first heard about this engine cycle in a Youtube video, I kicked myself for not seeing it coming.
Even so, it is heartening to know that there are dramatic advances still to be found in the old internal combustion engine.
Innovation will never die.