Mazda believes reducing vehicle greenhouse gas emissions is more complicated than simply switching from internal-combustion engines to battery-electric propulsion. If the electricity produced to charge batteries is not produced sustainably, then their "tailpipe" emissions are just moved to the powerplant.
So, the automaker has pushed deeply into the new frontier of using compression ignition technology in gasoline engines. The most advanced version of its Skyactiv production-engine series is called the Skyactiv-X. It operates using both compression and spark ignition — essentially combining the features of a diesel and gasoline engine — to increase fuel economy and cut CO2 emissions. Mazda calls its proprietary system SPCCI, for spark-controlled compression ignition. It's available in the mild-hybrid Mazda3 in Europe.
Adding to the base engine's complexity and cost are a supercharger, advanced ignition technology and an ultra-high-pressure fuel-injection system. Mazda says Skyactiv-X has been designed to work as a standalone or paired with an electric motor and battery power.
Mazda promises increased efficiency, power and torque, and lower emissions than earlier gasoline and diesel Skyactiv engine variants.