Mazda’s commitment to perfecting the internal combustion engine leaves the company swimming upstream in this era of downsizing. Now, Mazda engineers are going all out with the development of the SkyActiv-X engine, set to be the world’s first commercial petrol engine to feature compression ignition, controlled using a spark plug in this case.

At the recent Los Angeles Auto Show, Jay Chen and Yoshiaki Yamane, powertrain engineers at Mazda North America, explained to Road & Track that the company simply doesn’t believe in downsized turbo engines and Continuously Variable Transmissions (CVT). “We’ve determined that CVTs and downsized turbocharging are not the solutions we want. It doesn’t drive like a Mazda,” Chen told the publication.

According to Chen, the strategy for a typical small-displacement turbo engine is just “trying to get great fuel economy and engine efficiency in one very small operating point.” This sure provides great on-paper fuel economy figures, but not in real-world conditions. Plus, tiny force-fed engines are just not that nice to drive, said Chen.

Out in the real world, Mazda’s regular SkyActiv engines still outperform a downsized turbo, both in terms of CO2 output and drivability, with the latter being core to the company’s Jinba Ittai philosophy. Even today, Mazda’s range of rev-happy SkyActiv-G petrol engines feature high compression ratios (a minimum of 13.0:1) for lean burning, while the SkyActiv-D diesels have a low 14.0:1 compression ratio (low for a diesel).

“We don’t necessarily believe in what the other guys are doing. We believe the internal-combustion engine is here to stay and we believe our approach is better. In the past, Mazda has tried to compete head-on with Toyota and Honda as a mainstream headline commodity manufacturer, and we hurt from that that,” added Chen. In fact, the SkyActiv offensive, which began in 2012, proved to be successful when Toyota took a 5% stake in Mazda.

“They [Toyota] are actually starting to see the benefits of how we do things. Obviously Toyota’s new engine is very similar to our SkyActiv-G engine. They envy us and our ability to challenge and do things differently. Their deal is that they want to study our engine expertise. That’s why we’re not chasing CVTs or downsized turbos, or conventional hybrids,” said Chen.


The 2.5 litre SkyActiv-G Turbo in the CX-9 is Mazda’s only turbocharged petrol engine

Despite its faithful push for naturally-aspirated motors, Mazda is not a complete stranger to force-fed engines. The just-launched Mazda CX-9 features a turbocharged 2.5 litre four-cylinder Skyactiv-G engine (also making its debut on the new Mazda 6), but the turbo is purposely designed to recreate the low-end torque characteristic of a larger V6 engine, hence the low output (228 hp, 420 Nm). Remember, the previous CX-9 had a 274 hp/367 Nm 3.7 litre Cyclone V6.

However, Chen stresses that SkyActiv-G turbo mill isn’t a performance-car engine, so don’t expect to see it in a new Mazdaspeed 3 (Mazda 3 MPS) or the MX-5. “The Miata is just recently new,” he said, adding that its “environmental impact is very, very low.” Interestingly, Mazda filed a patent for a triple-charged longitudinally-mounted engine in August, but that may not debut until after the second-generation Skyactiv-D engines are released in 2020.

Now, back to compression ignition. The new SkyActiv-X engine actually features a supercharger, but its purpose is not to increase output. Dubbed a “lean supercharger,” its primary function is to shove more air and exhaust gas recirculation (EGR) back into the cylinder. “We avoid the term ‘supercharger,’ because people think 2.0 liter supercharger, and they have a certain power output expectation.

Mazda is banking big on its new SkyActiv-X compression ignition engine, going on sale 2019

“In order to achieve compression ignition, we’re using air-fuel ratios of up to 50:1, so we need to shove more air in,” said Chen. So, the supercharger is actually physically putting more air and EGR back into the cylinder, plus the same amount of gas.”

Yamane added, “Its purpose is to appropriate air into the intake, and therefore, it’s not so big.” Big here refers to the size of the supercharger; Yamane said engines with big superchargers often aren’t very fuel efficient. “This additional air supply makes close to the ideal combustion condition,” he added.

Enthusiasts will be happy to know that SkyActiv-X can be paired with a manual gearbox, and there’s a good chance Mazda will introduce that combo. The Hiroshima-based carmaker is testing the SkyActiv-X with automatic and manual transmissions as we speak.

The good news is, the new compression ignition engine won’t feel too different from the company’s current crop of engines, just more responsive. “Drive your Mazda 3 in a lower gear. Then you’ll know exactly what this drives like,” Chen said. The interviewees were so proud of the SkyActiv-X that it spurred Chen to call it the “holy grail” of engines, while Yamane considers it the “ideal state of the engine world.” Bold claims indeed.

But what about the good old rotary engine? According to Yamane, Mazda has a small team of less than 20 individuals who are developing the engine, although no concrete plans have been made to bring it to production. Mazda is a small company, said Chen, so it has to focus its limited resources on the SkyActiv family.

The Skyactiv-X, which is said to combine the advantages of petrol and diesel engines to produce low emissions and increased performance, will make its debut in 2019. Whether or not its maiden voyage takes place in the next-generation Mazda 3 remains to be seen. For now, read more about what SkyActiv-X technology entails here.