While other manufacturers are downsizing engines and sticking turbos anywhere they’ll fit, Mazda has attempted to maintain a home for naturally aspirated motors — engines it believes should be sized appropriately for their intended application. On paper, this appears to be giving the competition an edge. Yet Mazda remains committed to offering the right tool for the job, introducing naturally aspirated Skyactiv engines with unusually high compression ratios. The latest, Skyactiv-X, combines spark-controlled gasoline combustion and compression-ignition diesel tech with a 24-volt mild-hybrid system.

The system delivers 178 horsepower and 164 lb-ft of torque in 2.0-liter guise, plus MPG improvements of up to 20 percent vs the old Skyactiv-G. But there’s a problem. With Mazda attempting to go upmarket, an economy-focused powertrain has to deliver in whatever region it’s sold, and introductory Skyactiv-X units are now viewed as too small for the United States. The result? The technology’s delayed arrival in North America, despite its deployment via the new 2.0 liter found in the 2020 Mazda 3 and CX-30 sold in Japan and Europe.

Eiji Nakai, Mazda’s executive officer for powertrain development, said as much to Automotive News. “We think this Skyactiv-X can be used for larger engine displacement in the future, in line with our product planning,” he explained. “This technology is applicable to other engine displacements.”

U.S.-spec Mazdas will continue utilizing the old 2.5-liter mill in lieu of the 2.0-liter Skyactiv-X, though Nakai said the manufacturer is already running simulations to assess how the latest Skyactiv technology would perform on engines with larger displacements.

Mazda engineer Yoshiaki Yamane believed such units would be better suited to American driving habits, where drivers tend to prioritize power for longer-distance expressway driving at the expense of maximizing their fuel economy. It’s not that the U.S. doesn’t appreciate high mpg estimates — quite the contrary, it’s just not in the habit of making that a keystone of any automotive purchase. “Maybe U.S. customers require more power, because fuel economy is not the top requirement,” Yamane mused correctly.

From Automotive News:

Mazda is developing a new large-vehicle architecture that will arrive in the fiscal year ending March 31, 2023. That platform is expected to accommodate a larger-displacement Skyactiv-X engine. Skyactiv-X represents Mazda’s push to develop a more fuel-efficient, yet spunky, engine line. It harnesses a technology Mazda calls spark-controlled compression ignition, which blends the fuel economy of a gasoline engine with the power of a diesel. Mazda says Skyactiv-X technology delivers sizable improvements in fuel economy and torque, along with smoother acceleration.

While TTAC garnered some face time with a Mazda3 Skyactiv-X prototype and has gone into great detail as to how the new motor works, we also knew it’s entry to the U.S. was probably going to be delayed. Mazda has been very careful not to promise anything, instead expressing a desire to make the technology global by rolling out versions that are best suited to specific regions. For the United States, that means the 186 horsepower/186 lb-ft of torque 2.5-liter unit carries over. Meanwhile, Canadian shoppers continue to have access to the old 2.0-liter Skyactiv-G making 155 hp and 150 lb-ft, plus additional transmission options.

Pricing is another issue. In the Japanese market, the Mazda 3 with Skyactiv-X is now the most-popular powertrain on offer. It stickers 27 percent higher than the base 2.0-liter Skyactiv-G gasoline engine, offering a 9 percent improvement in fuel economy and a 15 percent increase in overall horsepower. North American customers might it find harder to rationalize spending more on a vehicle who’s party piece is slightly improved overall efficiency — especially when that money could be used to buy something larger and more powerful.

Unfortunately, Skyactiv-X simply requires too much fancy hardware to be sold for less. In addition to all the trick compression, spark and hybrid stuff, there’s also a supercharger. The unit, however, is not responsible for boosting power — it’s just there to help lean out the motor, which is how Mazda can continue to claim it’s providing “naturally aspirated” engines.

No one reviewing them seems to mind. Outside of a few diesel-like startup sounds, there’s not much to give away Skyactiv-X as anything abnormal. We’re not gobsmacked that it has become the dominant powertrain option (for the Mazda 3) in Japan. But does it make sense for the automaker to chase down complicated Skyactiv technologies when the rest of the industry is running with small-displacement turbos and widespread electrification?

Mazda thinks so. It believes it can do more in the short term by promoting exceptionally efficient motors, generating more market appeal than present-day EVs. But Mazda has also said that the regulatory presumption that the emissions of an electric vehicle are effectively zero are disingenuous, and has previously cited the massive amount of energy required for their production and shipping. The automaker has long been a proponent of calculating how much pollution is created by the energy generated to build and power EVs, saying that’s the only way to truly assess their long-term environmental impact.

[Image: Mazda]