Mazda responded differently to current downsizing measures, trying to be confident in its naturally aspirated engines. The Japanese manufacturer developed the Skyactiv range of engines and transmission and managed to keep up the pace with other manufacturers that choose downsizing.

Now Mazda goes even further with the new Skyactiv-X generation of engines. It is the world’s first commercial gasoline engine to use compression ignition, in which the fuel-air mixture ignites spontaneously when compressed by the piston.

A proprietary combustion method called Spark Controlled Compression Ignition overcomes two issues that had impeded commercialization of compression ignition gasoline engines: maximizing the zone in which compression ignition is possible and achieving a seamless transition between compression ignition and spark ignition.

This new proprietary combustion engine combines the advantages of gasoline and diesel engines. Compression ignition and a supercharger fitted to improve fuel economy together deliver engine response and increase torque 10 – 30 percent over the current SKYACTIV-G gasoline engine.

Compression ignition makes possible a burn that improves engine efficiency up to 20 – 30 percent over the current SKYACTIV-G, and from 35 – 45 percent over Mazda’s 2008 gasoline engine of the same displacement. SKYACTIV-X even equals or exceeds the latest SKYACTIV-D diesel engine in 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.