While most carmakers are moving towards full electric or electrification to meet the stringent emission norms, Mazda has come up with a gasoline engine that uses diesel engine technology to achieve better fuel efficiency.
The Skyactiv-X, which Mazda claims to be the world’s first gasolene engine to use compression ignition – where fuel-air mixture ignites spontaneously when compressed by the piston. Mazda explains that the 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.
Combining the advantages of both gasoline and diesel engines, the new engine promises an outstanding environmental performance, power and acceleration performance. A supercharger has also been fitted to improve fuel economy, and 10–30 percent increase in torque over the current Skyactiv-G gasoline engine.
Overall, the technology 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, says Mazda.
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, added the company.
Mazda plans to commercially introduce the Skyactiv-X in 2019.