For the test drive, Mazda housed the Skyactiv-X engine, below, in a prototype Mazda3 hatchback.
IRVINE, Calif. — Mazda’s Skyactiv-X is a volatile symphony inside a combustion chamber.
Combining characteristics of diesel and conventional gasoline engines, it uses spark plug ignition to “control compression ignition” in a feat likely to give Mazda engineering bragging rights upon its slated 2019 debut.
But one crowd won’t notice the chaos under the hood: consumers. And that’s the way Mazda wants it.
A test drive of Skyactiv-X shows Mazda has tamed the madness within, as shown by the peppy yet unassuming ride that it supports.
The technology is still being perfected. Engineers pointed to several areas that will be refined before its release — an engine knock that can creep in at times, for instance.
But the engine doesn’t drive like a shaky science project. It feels normal, which is a breakthrough for the Mazda team.
“That’s the goal,” said Edward Otani, a powertrain engineer at Mazda North American Operations, during a demonstration drive last week here. “Consumers don’t care how complex it is. When you drive this, it feels like a normal car.”
Skyactiv-X is the next step in Mazda’s quest to squeeze more potential from the combustion engine. Although the automaker plans to introduce a mild hybrid electric vehicle in 2019, a battery EV in 2020 and a plug-in hybrid after that, it isn’t done refining the gasoline engine.
With Skyactiv-X, Mazda is targeting a 20 percent improvement in fuel economy over the Skyactiv-G system used across Mazda’s lineup.
Mazda says it’s the world’s first commercial gasoline engine to use compression ignition, in which the fuel-air mixture ignites spontaneously when compressed by the piston. It’s tuned to run on 87-octane gasoline, but powertrain engineer Jay Chen said it can operate on higher grades up to 93 because of the compression ignition process.
Mazda SkyActiv-X Engine Technology
A video from Mazda giving a visual understanding of their new Spark Controlled Compression Ignition technology, which promises better fuel economy like a diesel, without the emissions penalty.
For the test drive, Skyactiv-X was housed in a prototype Mazda3 hatchback built on the seventh-generation Skyactiv vehicle architecture. The platform includes a simplified wheel motion, improved seat structure and quieter ride.
The efficiency gains Mazda is trying to elicit go beyond the combustion cycle. Mazda said the new engine has a mild hybrid component with its stop-start setup. Skyactiv-X harnesses energy during deceleration to power the vehicle’s electrical system, an outgrowth of Mazda’s i-Eloop regenerative braking system, says Dave Coleman, manager of vehicle dynamics engineering for Mazda North American Operations.
Normally, Coleman said, “fuel is being burned just to turn the alternator and just to run the supercomputer that’s running the engine, your fan, lights and all that’s going in the car. That’s a nonnegligible amount of power it takes to power that stuff. If we can power that stuff just with the inertia of stopping the car, instead of with gas, we’re better off.”
There are still a few points to iron out before the Skyactiv-X reaches the market.
For one, Mazda has to satisfy U.S. emissions standards. Otani said that optimizing engine performance and fuel economy to meet the emissions requirements is “going to definitely be the next challenge in the steps moving forward.”
And Mazda engineers aren’t done trying to increase engine efficiency. “There’s a lot of heat that’s being wasted,” Otani said. “How we recoup a lot of the lost heat is going to be the next step in improving the technology.”
Although Skyactiv-X is complex, Mazda is encouraged by the normalcy it provides. Most consumers won’t understand the breakthrough under their hoods, but Coleman said he doesn’t mind.
“All they want to know is the engine feels great, and does exactly what [they] want it to do,” he said. “If that’s all they know about it, that’s good enough.”