Mazda Is Making a New Gas Engine: Skyactiv-Z

• Skyactiv-Z will be a four-cylinder engine.
• It will replace both Skyactiv-G and Skyactiv-X.
• Lessons learned during development will be applied to the six-cylinder engines.

Financial news always tends to be dull. But every now and then, a car company sneaks in a nugget. Such is the case with Mazda’s latest document on how it fared in the most recent quarter. In an amalgam of boring numbers, there’s news about a gasoline engine we haven’t heard of before: Enter the Skyactiv-Z.

It’s bound to replace both the Skyactiv-G and Skyactiv-X. While the former is prevalent, the latter with its homogeneous-charge compression-ignition (HCCI) technology never really caught on. Mazda intends to eventually discontinue both and replace them with Skyactiv-Z, which will be another four-cylinder mill. Lessons learned during development will help the Zoom-Zoom company improve the larger six-cylinder engines as well by making the inline-sixes run cleaner.

Since the first cars with this engine won’t come out until 2027, Mazda is tight-lipped for now. It does say the four-pot will utilize the lambda one combustion method to “achieve high thermal efficiency by realizing super lean burn combustion over a wide range from low to high rpm, to provide excellent environmental performance and driving performance.”

Lambda (“λ” in the Greek alphabet) represents the air-fuel equivalence ratio. When λ = 1.0, the amount of air is perfectly balanced with the fuel during the combustion process. In this scenario, efficiency is optimized, therefore reducing emissions. Long story short, it means that all the fuel is burned, minimizing harmful pollutants.

Mazda intends to utilize Skyactiv-Z initially in cars sold in Europe and the United States. The engineers are hard at work to make the four-pot unit comply with Euro 7 regulations as well as EPA’s Tier 4 standards.

In related news, the Japanese brand intends to streamline its engine offerings by focusing on fewer powertrains. As for the rotary engine, Mazda is “making smooth progress” after reinstating the dedicated team back in February: “The development of emission compliance for the rotary engine is very challenging, but we are making good progress.”

At the end of May, Mazda together with Toyota and Subaru held a joint conference to announce new combustion engines. Toyota has already detailed its new ultra-efficient four-cylinder units while Subaru recently talked about the Crosstrek’s new frugal hybrid setup.

And now for a bit of speculation. Since the next MX-5 will still have a combustion engine (even though Skyactiv-G is gone), it could mean the fifth-gen Miata will be powered by a Skyactiv-Z engine. It remains to be seen whether some form of electrification will be baked in. Hopefully, it will be minimal so as not to add too much weight to the nimble roadster.