Mazda’s fleet is the most fuel-efficient in the United States despite not having a single hybrid or electric vehicle.

Climate change is the real deal, and governments around the world are starting to clue-in. That’s why most world governments have started tightening regulations surrounding greenhouse gas emissions and fuel economy for vehicle fleets. And despite not having a single EV or hybrid-electric vehicle, Mazda has the best fuel economy of all car manufacturers in the US.

Not only that, Mazda has held that title for 5 years in a row.

So how’d they do it? “We are taking [the] approach of well-to-wheel, not just tailpipe emission,” Mazda North America CEO Masahiro Moro told AutoGuide. Moro also went on to say that he believes a highly efficient internal combustion engine is still the best way to go based on how energy is generated around the world.

“I think this is [a] much better way because [of] how each country generates electricity,” he said. Most countries still generate the bulk of their power by burning coal, oil, or natural gas, so a sudden switch to battery-powered cars isn’t as green as many people would believe. Very few US states generate their power from clean nuclear or hydroelectric power plants, with most still getting their power from oil or coal.

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For now, the best thing for the automobile to do to fight climate change, says Moro, is to become extremely efficient at burning gas. That’s why Mazda has developed the new SkyActiv-X engine. It uses something called "spark-controlled compression ignition" to provide diesel-engine fuel economy in a motor that still burns regular unleaded gasoline.

SkyActiv X
via Mazda

SkyActiv-X will arrive in Europe first as regulations are tighter there, while the first generation of SkyActiv engines will remain in the US until domestic regulation become more strict.

That said, Mazda understands that they won’t be able to keep using internal combustion forever. They expect to bring their first electrified powertrains to the US market by 2025, with Europe happening a bit sooner.

As for the legendary rotary engine, Moro said we might see it live on as a small generator for electric cars, but not to hold your breath.

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