By optimizing the split-cycle concept, the Scuderi engine is expected to reduce NOx emissions up to 80 percent and improve fuel efficiency by 50 percent, compared to a conventional gasoline engine.

FORBES: How To Get 50 MPG Out Of Your Gasoline Engine

That same car with a conventional small gasoline engine would probably get 15 kilometers per liter and use 1, 100 liters.

FORBES: Magazine Article

The company announced at the Los Angeles Auto Show that the U.S. version of its Mazda 6 midsize sedan, which got a major redesign for the 2014 model year, will offer a new four-cylinder diesel engine, in addition to a conventional four-cylinder gasoline engine.

FORBES: Mazda Bets Big On Diesel With The All-New 2014 Mazda 6

Conventional hybrids use mainly the gasoline engine for propulsion, drawing on the electric drive and batteries only occasionally to (impressively) improve gasoline efficiency.

FORBES: The Automobile Shifts Gears

Nevertheless, conventional hybrids are still locked into the oil economy, with a drive shaft directly connected to a gasoline engine.

FORBES: Magazine Article