Charles referred me to EcoMotors, Esquire 2010 Car Awards/Innovation of the Year:
Where typical engines have one piston per cylinder, hammering up and down like a fist against a ceiling, the OPOC — which was designed by a former chief powertrain engineer at Volkswagen — has two pistons per cylinder that come together and pull apart like hands clapping. The pistons travel only half as far, meaning they can complete a cycle twice as fast, which lets OPOC generate twice the power of an equivalent standard engine — the same power in a package half the size. Further innovations in fuel delivery and exhaust and the innate efficiency advantages of the two-stroke cycle mean the system offers, conservatively, 50 percent reduction in fuel usage with no reduction in power, no increase in emissions, weight savings of 50 percent, and cost savings of 20 percent.
EcoMotors International has attracted Bill Gates and Vinod Khosla as venture investors for a $23.5M B round. To achieve zero carbon emissions we need to transition light vehicles to EV, all electric drive trains. But that will take several fleet turnovers, and electric generation in most countries is far from zero carbon. While fossil power generation is replaced by nuclear and a bit of wind/solar we need to cut internal combustions emissions radically. Ecomotors may have part of the answer.
Speculation: a relatively light vehicle like a Honda Civic powered by this engine is likely to be simpler, cheaper and fuel efficiency competitive with hybrids like the Prius.