Mazda shares development highlights of Skyactiv-X powertrain, electrification goals

Mazda has announced its plans under the company's Sustainable Zoom-Zoom 2030 strategy. Mazda provided details of the plans and offered a look at a prototype engine and new platform, including a brief drive, to select media and analysts, including IHS Markit.

IHS Markit perspective

  • Significance: Mazda has set out the company's strategy for the period up to 2030, which is entitled Sustainable Zoom-Zoom 2030. In 2019, Mazda plans to launch an engine called Skyactiv-X, which combines combustion and spark ignition for claimed dramatically improved fuel economy.
  • Implications: One of the keys to Mazda's plans is the ability to develop programmes more quickly than many competitors, despite the company's smaller size and fewer resources than larger automakers. The Skyactiv-X powertrain is an example of such a programme, with the engine's production set for 2019.
  • Outlook: Amid industry announcements of increasing levels of electrification, Mazda appears to be developing an ICE technology that will position it well for future electrification programmes. The Skyactiv-X engine technology is also aligned with Mazda's strategy to 2030 and its focus on improving driving pleasure and delivering fuel-economy and performance improvements outside of the testing environment.

Mazda issued a press release in August outlining several company objectives for the period up to 2030, as part of its Sustainable Zoom-Zoom 2030 strategy. The Japanese automaker also recently invited media and industry analysts to sessions offering a more in-depth look at the company's Skyactiv-X technology and new platform. IHS Markit attended on 29 August and here reports on the development of the Skyactiv-X engine.

Mazda's objectives through 2030 include working towards addressing carbon dioxide emissions in well-to-wheel production, considering the vehicle's full lifecycle of emissions. The company has set targets for reducing corporate average well-to-wheel CO2 emissions to 50% of 2010's levels by 2030, with a further goal of cutting CO2 by 90% by 2050, from a corporate perspective. The emphasis on well-to-wheel emissions also means that Mazda will balance this with its approach to electric vehicles (EVs). Rather than targeting EVs for their own sake, Mazda will place emphasis on the full impact of powertrain choices. Mazda will continue to perfect the internal combustion engine, as it believes continual improvement of ICEs will make the greatest contribution to reducing CO2 emissions. Mazda expects ICEs to figure prominently in vehicle propulsion for decades. However, Mazda will combine its ICE efforts with electrification, as is true of most automakers. According to Mazda, "With a 30% fuel economy improvement, a Skyactiv engine-powered car will emit the same amount of CO2 as an EV using electricity generated by LNG [liquefied natural gas], the 'cleanest' of thermal power generation methods in terms of CO2 emissions." Mazda expects the Skyactiv-X technology to deliver that 30% improvement in fuel economy. In other words, Mazda is looking to find improvements in ICEs that will ultimately deliver the same reduction of CO2 emissions as the well-to-wheel impact of an EV. Mitsuo Hitomi, Mazda managing executive officer and senior technical fellow in charge of the technical research centre and integrated control system development, stated to IHS Markit that one benefit that the automaker expects from its development of the Skyactiv-X engine technology is a smaller hybrid system will be used with the engine to achieve comparable performance. This will lower the cost of the hybrid system by a greater degree than the increase in cost of the engine, although the specific details of this were not provided by the company at this stage.

From 2019, Mazda will begin introducing EVs and other electric drive technologies, deploying solutions in regions "that use a high ratio of clean energy for power generation or restrict certain vehicles to reduce air pollution", said the company. Mazda's efforts at electrification will reduce the risk of shifting emissions from tailpipe to electricity generation, while including efforts to develop technology to compete in markets that mandate drastically reduced emissions or specifically call for increased electrification.

Mazda's electric powertrain future

While the initial announcement indicated Mazda's plan to introduce the Skyactiv-X engine in 2019, the recent presentation provided more detail on the rollout of electrified powertrains and the targets for Mazda's future powertrain strategy. Hitomi also said that Skyactiv-X is not Mazda's end-goal, only the next step, and that the company's powertrain technology will continue to evolve.

Among the elements of this is that Mazda is focused on maximising greenhouse-gas reduction in real-world conditions, and Mazda will develop powertrain technologies that may sacrifice performance in regulatory testing in favour of real-world performance. By 2030‒35, Mazda's full powertrain line-up will consist completely of pure EVs and electrified ICE propulsion systems. At this point, Mazda has not indicated its plans to enter the field of fuel-cell vehicles. Mazda projects that, by 2035, 84.4% of new-car sales will still be using ICE, 11.2% will be EVs, and 4.4% will be fuel-cell EVs.

After introducing i-stop and i-eloop, using brake regen and idle stop to improve fuel economy, in 2019 the next phases of electrification will arrive. Mazda plans a mild HEV and a BEV in 2019, along with the Skyactiv-X gasoline (petrol) ICE. In 2020, Skyactiv-D generation two will be launched, improving diesel emissions. The company's first plug-in hybrid electric vehicle (PHEV) is not planned to arrive until after 2021, however.

Mazda's forward strategy will continue to include the Skyactiv-G and Skyactiv-D powertrains, along with Skyactiv-X. Leveraging its model-based development programme, Mazda intends to force process innovation, with common architectures and flexible production, to develop "unique, world-leading products with the most appropriate technologies for each market", the automaker said. Advancements will continue for manual and automatic transmissions and Skyactiv body and chassis technology. However, Hitomi told IHS Markit that advancing past six forward gears may not be necessary to reach fuel-economy targets.

Skyactiv-X: SPark controlled compression ignition

When news of Mazda's new compression ignition engine surfaced in August, many referred to it as homogeneous controlled combustion ignition, which would essentially be applying the combustion ignition process of a diesel engine to a gasoline engine. This has been in development by several manufacturers, including drivable prototypes, but this is not what Mazda has developed. Mazda, recognising that the controlled combustion ignition is not possible without a controlled spark, it has combined spark and combustion ignition, for what it calls SPark Controlled Compression Ignition (SPCCI). The system and an outline of Mazda's development was presented by Ichiro Hirose, managing executive officer in charge of powertrain development. Mazda was looking to increase the ratio of air to fuel, for a leaner burn, which would enable reduction of combustion temperature, reduce cooling losses, and increase the amount air for a given level of torque, reducing pumping loss.

Mazda has developed technology that enables it to completely control the switch between combustion types (spark or pressure) to expand the operation region of compression ignition. Skyactiv-X uses the spark plug as a control factor to provoke and control the timing of the compression ignition. As the spark ignition is used to create a small fireball that will enable compression ignition, the air/fuel mixture for the spark ignition is lean enough that little nitrogen oxide (NOx) is produced and the lean burn benefits of compression ignition are realised. SPCCI uses in-cylinder sensors, a high-pressure fuel system, and high response air supply (a Roots-type blower). The benefits to driving, according to Mazda, include improved launch response to the throttle pedal, as low resistance of the throttle valve allows intake air to enter the cylinder without delay, as well as expansive acceleration at high rpm. In terms of fuel economy, the system improves fuel consumption rates as well as creating a flat fuel consumption curve which will contribute to little difference in real-world fuel economy. Fuel economy is not as adversely impacted when the engine is under higher load (rpm): performance is not penalised by higher rpm driving, which benefits Mazda's priority for driving feel and performance.

IHS Markit also had the opportunity for a test drive, driving two cars in the neighborhood of the Mazda R&D centre near Frankfurt, Germany. Mazda made available cars with the next iteration of Mazda's Skyactiv platform hidden under modified Mazda3 sheet metal and prototypes of the Skyactiv-X engine under the hood. Attendees had the opportunity to drive a car equipped with Mazda's 6-speed manual transmission and another with the 6-speed automatic transmission. According to data provided by Mazda engineers, gathered from my specific drive, the Skyactiv-X with the automatic transmission delivered 37.3 mpg, while the Skyactiv-G would have delivered 32.2 mpg; in the city portion, my Skyactiv-X mpg was 38.6. With the manual transmission, there was stronger improvement. Total mpg for the drive, which included city and autobahn stretches, was 34.1 mpg, compared with the 28.3mpg today's Skyactiv-G would have delivered. There is still calibration work to settle some knock, particularly when mated to the manual transmission. However, power and torque were easily accessible and the new engine feels like the old engine, but better. The first Skyactiv-X engines are 2.0-litre 4-cylinder units, with Mazda is expecting the new engine to meet or exceed the efficiency of today's 2.2-litre Skyactiv-D; that target would make it 20‒30% more efficient than today's Skyactiv-G engine, with less cost than the diesel requires.

Outlook and implications

Mazda has successfully reduced product development cycles through its model-based development process and has developed a solution for applying the benefits of compression ignition for gasoline engines. Against the backdrop of multiple announcements of increasing levels of electrification, Mazda appears to be creating a base ICE technology that will position well for future electrification programmes. The Skyactiv-X engine technology is a significant step forward for the company, and is aligned with its strategy of improving the real-world experience, both in terms of improving driving pleasure and working to ensure that fuel-economy and performance improvements are accessible outside of the testing environment.

Regarding Mazda's efforts toward electrification, there is little detail beyond target dates at this point, although Skyactiv-X is being developed with the expectation that it will slot well into those future applications. Mazda's commitment to increasing electrification of its propulsion systems is within general market trends, and follows high-profile statements from premium brands including Volvo, BMW, and Jaguar about targets for electrification. IHS Markit expects that the move towards electrification is not so much a reaction to the loss of trust consumers might have in diesel technology of late, but a market necessity for meeting increasingly difficult global emissions and fuel-economy standards. Several governments have recently discussed banning diesel engines or all ICE units, and forcing automakers to offer only electrified vehicles, but many of those targets leave plenty of time for successive politicians to tone them down and none has formalised them into specific laws yet. Regardless, the pressure is on and Mazda is not going to be left behind in the shift.

IHS Markit estimates that, in 2017, about 54% of engines installed in light vehicles will have some form of electrification, including stop-start systems. By the end of the forecast period, 2029, IHS Markit projects nearly 80% of all vehicles produced will have engines with some form of electrification. Global vehicle production over this time period is forecast to increase from about 94.9 million units to about 114.8 million units.

About this article

The above article is from AutoIntelligence Daily by IHS Markit. AutoIntelligence Daily provides same-day analysis of automotive news, events and trends.​​​​​​ Get a free trial.


Filter Sort