The rumours were true. Mazda is indeed developing what it bills as the world's first commercial petrol engine to use compression ignition.

In a statement on its long-term vision for technology development, the Japanese automaker provided some details about its next-generation compression ignition petrol engine, which it revealed would also employ supercharging and be dubbed Skyactiv-X.

Mazda said that a "proprietary combustion method called Spark Controlled Compression Ignition overcomes two issues that had impeded commercialisation of compression ignition gasoline engines".

The first issue is maximising the zone in which compression ignition is possible, while the second is achieving a "seamless transition" between compression ignition and spark ignition. This suggests, as previously reported, that Mazda's new engine will see conventional spark plugs retained and used in conjunction with compression ignition.

"This new proprietary combustion engine combines the advantages of gasoline and diesel engines to achieve outstanding environmental performance, power and acceleration performance," the automaker said.

According to Mazda, the combination of compression ignition and a supercharger will both improve fuel economy and deliver "unprecedented engine response", with a 10 to 30 percent increase in torque over the current Skyactiv-G petrol engine, thanks to a "super lean burn".

Mazda added that the new engine would even "equal or exceed" its latest diesel mill in terms of fuel efficiency.

"With high efficiency across a wide range of rpms and engine loads, the engine allows much more latitude in the selection of gear ratios, providing both superior fuel economy and driving performance," it said.

Original article from Car