A group
of MIT professors have invented a new type of ethanol-boosted, turbocharged, gasoline engine that promises to be almost
as efficient as a gas-electric hybrid, but at a much lower cost. The main idea behind the concept is to reduce fuel
consumption by reducing engine size, adding turbo charging, and increasing the engine compression ratio. I’m sure
many of you are thinking this doesn’t sound like anything you haven’t heard before, and I would have to
agree with you so far.
The novelty of the idea comes in the form of a separate injection of ethanol to avoid
combustion knock. Combustion knock happens when gasoline spontaneously combusts, as opposed to the combustion initiated
by the spark plug, and can cause significant engine damage. This spontaneous combustion happens most frequently when
the engine is operating at a high output or running at high speeds. Turbo charging and increased compression ratios
increase engine efficiency, but also contribute to increased risk of engine knock. In addition, when the engine is
downsized substantially, it will be operating at high output and at higher engine speeds more frequently, again
increasing the changes of engine knock. To avoid engine knock, the MIT professors propose to inject small quantities of
ethanol into the combustion chamber when the engine is operating at conditions that are prone to knocking. An increase
in fuel consumption of 30% is predicted. The main problem would be related to logistics, since consumers would have to
fill up an ethanol tank, but the interval might be as infrequent as an oil change.
[Source: The Technology
Review]