At a recent technical conference in Tokyo, Mazda’s powertrain managing executive officer Mitsuo Hitomi revealed plans for what Mazda has dubbed SkyActiv-3. The amount of energy in gasoline converted by a traditional engine to usable power and not lost to heat, friction or noise —to 56 percent, it can achieve emissions on a par with an purely electric car. That would require an thermal efficiency increase of about 27 percent from the SkyActiv-X that is still in prototype phase. Most gasoline engines achieve only 20 percent thermal efficiency.
The first generation of Mazda’s so-called SkyActiv-G and SkyActiv-D (for gasoline and diesel) engines started development in 2007. The goal, which Mazda achieved, was to improve its overall mpg across its car and crossover lineup by 30 percent without the use of hybrid or full-electric technology. The theory, says Mazda vehicle dynamics engineer Dave Coleman, is that whatever fuel savings or emissions reductions that can be squeezed out of internal combustion engines can still yield benefits when and if paired with electrifiction in the future.
SkyActiv-X is the next leap in optomizing internal combustion. Mazda says it will improve efficiency 20 to 30 percent over SkyActiv-G, itself a 35-45 percent improvement over a pre-SkyActiv Mazda engine.
Mazda is taking a holistic well-to-wheel approach when considering environmental impact. That means the emissions from the raw material to assembly to disposal stages of vehicle lifespan will all be considered. The source of electricity generation, whether natural gas or hydroelectric or renewable, for electric vehicles is also taken into account. When all that is factored in, Mazda believes it can reduce carbon dioxide emissions to 50 percent of 2010 levels by 2030, and to 90 percent of 2010 levels by 2050.
Hitomi did not give a timeline for SkyActiv-3, but the first SkyActiv-X equipped cars should hit the market in early 2019.