Mazda Is Quietly Killing One Of Its Most Unusual Engines

Mazda's Skyactiv-X may be disappearing, but its experimental combustion technology is helping pave the way for the Skyactiv-Z hybrid.

By: Anthony Alaniz

Oct 29, at 11:02am ET

Comment

Mazda’s most unusual engine is living on borrowed time. Mazda’s Skyactiv-X engine will power only one model in the United Kingdom and Europe, and the Japanese automaker is already developing its next-generation powertrains.

According to Auto Express, for the upcoming model year, Mazda will drop the 2.0-liter engine option from the 3, leaving buyers with just the 2.5-liter Skyactiv-G. Buyers can pair the G with a manual or automatic transmission, but it makes far less power.

The automaker will continue to offer the Skyactiv-X in the CX-30, but the engine might not survive alongside it. Mazda is developing the Skyactiv-Z hybrid powertrain to replace its current small-engine lineup.

What Made Mazda Skyactiv-X Different?

Mazda3 Prototype With Skyactiv-X Engine

Mazda’s Skyactiv-X engine pioneered a technology that several automakers tried to bring to market: a homogeneous-charge compression-ignition (HCCI) engine. Ford, General Motors, Honda, and others developed prototype HCCI engines, but none ever entered production.

Mazda launched its Skyactiv-X engine in 2019, powering the Mazda3 and CX-30 in certain markets. The automaker never offered it in the United States.

An HCCI engine combines diesel and gasoline engine technologies, and Mazda’s innovation was using spark to control compression ignition. The company calls it Spark Controlled Compression Ignition (SPCCI). The Skyactiv-X normally runs on a very lean air-fuel ratio, which is unpredictable.

To counter this, Mazda injects a small amount of fuel right at the end of the compression stroke. This creates a richer air-fuel mixture around the spark plug, which fires and ignites the new air-fuel pocket.

This rapidly increases pressure and temperature inside the combustion chamber, igniting the lean air-fuel mixture. This allowed Mazda to offer a more powerful, more efficient engine, but it never saw wide use.

Hybrid Is The Future

Despite the Skyactiv-X's numerous innovations and the effort Mazda put into bringing it to market, the automaker is developing a worthy replacement. Next year, Mazda will introduce its Skyactiv-Z hybrid engine.

What do you think?

View

Comments

The Skyactiv-Z will pair an all-new 2.5-liter four-cylinder engine with an in-house-developed hybrid system. The new CX-5 crossover will debut the powertrain by the end of next year, with lessons learned from the Skyactiv-X built in.

The Skyactiv-Z will evolve the company’s SPCCI technology, aiming for the engine to combust even leaner fuel mixtures. The new hybrid powertrain will also feature new heat-insulation technology that turns escaping engine heat into power.