2017 Mazda Mazda3 4-Door Sport Auto GrilleEnlarge Photo
It is important, Fujiwara explained, that the wells-to-wheels carbon emissions per mile of an EV are demonstrably lower than those from even the most efficient Mazda using the HCCI-based SkyActiv-X engine.
The company plans to cut the carbon emissions from its lineup in half by 2030—and by 90 percent in 2050—over base 2010 levels.
It takes the approach that accurate analysis of real-world carbon emissions requires looking at the wells-to-wheels carbon footprint of both electric cars and those with internal combustion engines.
The former includes the carbon emitted to generate the power that recharges the batteries, while the latter includes not just the efficiency of the combustion engine but also the carbon emitted in extracting, refining, and transporting liquid hydrocarbon fuels.
Those analyses and models exist, from a variety of researchers.
But Mazda is the first carmaker we know of that has suggested that not just fuel efficiency but wells-to-wheels carbon footprint is the appropriate measure to consider in comparing electric cars to the most efficient gasoline vehicles.
Electric-car wells-to-wheels emission equivalencies in MPG, May 2017 [Union of Concerned Scientists]Enlarge Photo
If the goal of reducing carbon emitted from road vehicles is, in fact, to slow release of the carbon dioxide that contributes to climate change, then that's exactly the right metric to use.
Mazda feels there's a lot of room left for efficiency in combustion engines.
While the most efficient engines now in production reach 40 to 42 percent thermal efficiency, the company's calculations suggest 55 to 60 percent is achievable, according to Ichiro Hirose, managing executive officer in charge of the company's powertrain development.
But, Fujiwara said, Mazda doesn't see any point within the next 10 years at which battery-electric cars with reasonable ranges can be sold profitably at prices that equal those of the most efficient conventional cars.
For context, the company's highest-production car globally is the Mazda 3 compact hatchback and sedan line, which starts around $19,000 in the U.S. this year.
The challenge of making the business case to build and sell those cars at mass-market prices, he said, is "quite severe."
Toyota chief Akio Toyoda (left) and Mazda chief Masamichi KogaiEnlarge Photo
Mitsuo Hitomi, Mazda's managing executive officer and technical center chief, said during the technical session that the company believes vehicles with far more efficient combustion engines will remain the largest part of the global market through 2035, and liquid fuels will dominate until 2040.
Meanwhile, Fujiwara said, the ability to create carbon-neutral synthetic hydrocarbon fuels that can substitute directly for fossil-fuel gasoline is a major opportunity to slash carbon emissions.
Still, like Toyota with hydrogen fueling infrastructure, Mazda can't make that happen alone—leaving calculations of the wells-to-wheels carbon emissions of its SkyActiv-X engines reliant on conventional gasoline made from fossil-fuel oil.
The question for Mazda over the next decade or so will be whether its engineers can produce engines that lower carbon emissions enough to match the falling carbon footprint of electric cars, as electricity grids around the world add renewables and decarbonize at a rapid clip.
Mazda provided airfare, lodging, and meals to enable High Gear Media to bring you this first-person report.