HIROSHIMA, Japan — Mazda Motor Corp. is claiming a breakthrough in gasoline engine design, saying it has solved the technical hurdles associated with homogeneous charge compression ignition (HCCI) technology that offers the fuel economy of diesel engines but without the soot or nitrogen oxide emissions.
This concept essentially achieves internal combustion through compression alone, without the need for spark plugs.
Mazda announced this week it plans to start offering the technology, dubbed SKYACTIV-X, in the near future.
"A proprietary combustion method called Spark Controlled Compression Ignition overcomes two issues that had impeded commercialization of compression ignition gasoline engines,” Mazda said: “Maximizing the zone in which compression ignition is possible and achieving a seamless transition between compression ignition and spark ignition.”
Mazda's design will still use spark plugs to achieve ignition under certain conditions such as low temperatures, but it has indicated that all other issues pertaining to this design have been solved successfully, with the company touting the "super lean burn" characteristics of this new engine.
The engine is expected to be 20- to 30-percent more efficient than the company's SKYACTIV-G family of engines, and an impressive 35- to 45-percent more efficient than the auto maker's 2008 engine with the same displacement.
Mazda's compression gasoline engine is promised to deliver 10- to 30-percent greater torque numbers than SKYACTIV-G engines, with Mazda planning to pair the new design with a supercharger. In addition, Mazda said that this new type of engine will permit much more latitude in selecting gear ratios, which will benefit fuel economy.
How soon will we see this new design in Mazda cars at the dealership?
SKYACTIV-X engines are promised to appear in production models in 2019, but the auto maker has not indicated in which models we'll see these engines first. The auto maker also has not said if its HCCI engines will replace the current crop of SKYACTIV-G engines entirely or if Mazda will opt for a slow rollout of this technology.
Mazda cautions the engine is still under development and that the boosts in efficiency it has cited are rough estimates, but it maintains that its engineers have achieved a real breakthrough, one that points the way to the future of internal combustion engines at a time when many auto makers are beginning to plan for an electric future.
Story is based on reporting by Jay Ramey, associate editor of Autoweek, a Detroit-based sister publication of Tire Business.