Mazda's new SkyActiv-Z engine

Steadfast, impressive and Euro-7 compliant

Nowadays, new combustion engines are a species on the verge of extinction. Most manufacturers are now only swearing by electric vehicles, relegating the combustion engine to a secondary role. But a few stubborn holdouts refuse to follow the trend. Mazda is one of them.

Already known for daring to launch inline six-cylinder gasoline and diesel engines in the era of downsizing, the Japanese manufacturer is now going even further. They are developing a brand-new 2.5-liter four-cylinder gasoline engine, named Skyactiv-Z, which will debut in the future CX-5 planned for late 2027. And this engine is no ordinary one: it is designed to meet Euro 7 standards in Europe, as well as LEV IV and Tier 4 standards in North America.

An optimized combustion, without compromising performance

Mazda promises significantly improved thermal efficiency and a much wider operating range compared to the current Skyactiv-G and Skyactiv-X engines. The Skyactiv-Z architecture capitalizes on the experience gained with the SPCCI (Spark Controlled Compression Ignition) concept, a combustion process that blends elements of both gasoline and diesel engines.

To recap: SPCCI allows a gasoline engine to operate with compression ignition while retaining the traditional spark plug ignition. This enables the efficiency of a diesel engine to be combined with the usability of a gasoline engine. On paper, it’s the holy grail. In practice, few manufacturers have mastered it. Mazda, however, is holding on to it and refining the formula.

A Euro-7 engine that doesn’t sacrifice power

Unlike the usual approach of downsizing engines to meet standards, Mazda is taking the opposite bet: maintaining performance while improving cleanliness. According to the manufacturer, a simple adjustment of current engines to meet Euro 7 standards would have resulted in a power loss of up to 30%. Thanks to the Skyactiv-Z, this compromise will not be necessary.

And as the cherry on top, the technology developed around the Skyactiv-Z will also be used to optimize Mazda’s in-house six-cylinder engines and even to further evolve rotary engines. The famous Wankel engine is making a comeback as a range extender (as seen in the MX-30 R-EV), and Mazda is already working on a more powerful bi-rotor version for the American market. This direction has been confirmed by the Iconic SP concept, which we hope to one day see on the streets.

WOT's opinion: Finally, a manufacturer that thinks like an engine builder

At WOT, we don’t hide our admiration for this approach. Seeing a manufacturer continue to invest in combustion technology, striving to optimize it rather than replace it, resonates with us.

Mazda is going against the grain, with an engine builder’s vision: to extract the best from combustion, meet regulations without distorting the character of the engine, and even push forward concepts like SPCCI that many have abandoned along the way. It takes expertise, perseverance, and a true technical culture to remain so persistent. And for us, that’s exactly what we love about this craft.