The automotive industry is rapidly moving toward a new era of downsizing and hybridizing conventional internal combustion engines or replacing such units with all-electric alternatives. Mazda, on the other hand, has been determined to prolong the life of ICE-powered cars by developing new technologies that make them more efficient.
Skyactiv is the name the Japanese carmaker uses to describe a revolutionary series of technologies that include new engines, transmissions, body, and chassis that are all built to achieve maximum efficiency.
Mazda takes inspiration for its complete makeover from its home city of Hiroshima, which thrived as a manufacturing hub in Western Japan at the beginning of the last century and rose from the ashes to regain its prosperity after the atomic bombing that occurred in August 1945.
Motivated by the need to meet increasing safety and environmental standards, most manufacturers are rushing to either downsize their existing internal combustion engines or ditch them altogether.
Mazda, on the other hand, got back to the basics in their quest of creating the ideal ICE and revised every fundamental component of traditional engines, making drastic changes that resulted in some of the most efficient internal combustion powerplants in the industry.
Their latest development is the Skyactiv-X, a revolutionary gasoline engine that was revealed in 2019 as part of the available drivetrains for the fourth-generation Mazda3.
In a traditional gasoline engine, the fuel-air mixture is ignited by the spark plugs whereas in diesel-powered units it ignites through pressure and heat alone, because the fuel is much more energy-dense.
This results in more air and less fuel going in, the main reason why a diesel is more fuel-efficient than a gasoline-powered engine.
The compressed ignition system they use also allows them to produce higher amounts of torque at low revs, but the main problem is they traditionally emit higher levels of toxic particulates that cause pollution.
The innovative Skyactiv-X aims to offer the best of both worlds, being able to mix the high torque and fuel efficiency of a diesel with the high-revving character of a gasoline engine.
To achieve that, the 2.0-liter inline-four uses the innovative Spark Controlled Compression Ignition (SPCCI) system, making it the first mass-produced gas engine to do so.
It works by compressing the fuel-air mix at a higher compression ratio, which allows it to operate much leaner and efficient than a traditional spark ignition engine.
When the compressed mixture approaches the point at which it would spontaneously detonate, a second injector then sends an additional charge of fuel directly on the spark plug.
This causes an almost instantaneous increase in cylinder pressure to a point where the rest of the fuel undergoes compressed ignition in a similar manner as diesel engines.
This results in a faster and more complete burn of the fuel-air mix than traditional gasoline powerplants. Using this technology, the Skyactiv-X can produce around 30% more torque than a typical direct-injection engine while also providing more power and a greater fuel efficiency.
The innovative engine has an output of 177 hp (132 kW) and produces 224 Nm (165 lb.-ft) of torque. It is currently available on the Mazda3 and CX-30 crossover SUV with either the six-speed SkyActiv-MT manual transmission or six-speed SkyActiv-Drive automatic.
Although Mazda introduced its own hybrid and all-electric powertrains, it will continue its quest of developing the most efficient ICE-powered cars on the market.