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Mazda Skyactiv-X Review | The revolution begins with a squeeze-bang

The matte black Skyactiv-X prototype looks like a rough Mazda3, perhaps reconstructed after a bad wreck by an over-enthusiastic owner of a spot welder and lots of gaffers' tape. Ribbed ducts poke out of the dash sending two breaths of conditioned air to no one in particular. Even its revolutionary engine, the thing we're here to experience, is entombed in a massive, nondescript cover to mask its unseemly noises. It's a wild, strange way to meet a very unconventional vehicle that promises diesel-like fuel economy, a wide torque band, and an exotic method for burning less gas than ever before. It takes a few hours for Mazda's engineers to explain the fundamental principles of operation. For more detail, read our Skyactiv-X Spark Controlled Compression Ignition explainer, but here's a very brief overview. Skyactiv-X marries some traditional gasoline engine characteristics with a novel form of compression ignition called SPCCI. The key for Skyactiv-X is to use very high compression in the cylinder and an extremely lean fuel-air mixture. Squeezed right to the cusp of getting hot enough to blow up all on its own (which is very hard to predict), a squirt of extra gas and a spark interject to cross that compression-ignition threshold in a controlled and predictable manner. See the animation below: That takes a few essential components to get just right. One is a massive amount of computer processing power and some pressure sensors in the individual cylinders, because the ambient conditions change how and when these things happen. Skyactiv-X uses a clutched supercharger to pump in additional air when needed to nail the mixture precisely, and high-pressure injectors to get the low ratios of fuel to disperse properly in the chamber. And since it operates like a conventional gasoline engine sometimes, it uses valve timing to lower the very high compression ratio so it doesn't reach combustion ignition in that mode. In practice, the Skyactiv-X runs in compression ignition mode most of the time. In practical terms, that means it drives like a torquey gasoline Skyactiv engine. The torque curve is broad and flat — diesel-like in that respect. That also means it can get away with using a six-speed transmission and a lower final drive for better response. There's enough grunt and economy together that Mazda can let the engine spin faster — at 60 mph, it's running at roughly 1,000 more RPM than a similar gas engine, with greater efficiency.

Mazda has right mix to chase 120,000 more US sales

The Mazda MX-5 Miata was named to Car and Driver magazine's Ten Best list for the eighth year in a row and for the fourteenth time overall. The CX-5 tops or comes in as runner-up on every AOL Autos staff poll we take on compact crossovers. The Mazda3 is a perennial favorite among auto critics. That's three clear, unquestioned winners in the Mazda showroom. So, why does Mazda seem to struggle sometimes for recognition and clarity in the marketplace?
For that, I chatted with Mazda North American Operations President, Jim O'Sullivan, who has run the outfit since 2003. O'Sullivan, a former Ford sales and marketing executive who came to Mazda from Dearborn, MI when Ford owned a controlling stake in Mazda, is one of the quieter, but very menchy, leaders in the industry whose longevity in the job speaks to the stability of Mazda.

Mazda's Tokyo concept foretells of rotary revival

Mazda has long been rumored to be planning a revival of its rotary-powered sports car. Some of those rumors may have come down to wishful thinking as much as concrete information. But now, on the eve of the Tokyo Motor Show, new details have come to light. The Japanese automaker is slated to unveil a two-door sports car concept, previewed in the teaser image above. Little in the way of firm information has been made available prior to the show car's debut, but sources are now citing senior company officials as confirming it has a rotary engine. "It is a two-door, two-seater, Mazda CEO Masamichi Kogai told Autocar. "It is a pure sports car design. We have MX-5 and another icon is a rotary sports car. We haven't talked about market reach but this would be in that segment." R&D chief Kiyoshi Fujiwara added: "People think rotary can not meet modern eco demands. The SkyActiv engineers worked on rotary and gave it cutting-edge tech. It is an essential part of our DNA and it [will] just be passed onto future engineers. It is synonymous with the brand. Some time in the future it will return and be called SkyActiv-R." The last time Mazda produced a rotary-powered model, of course, was with the RX-8, which ended production in 2012. That was preceded by three generations of RX-7, the first of which will be celebrating its 40th anniversary in 2018. If it manages to get the Wankel technology up to modern standards, that could provide just the right opportunity for Mazda to launch a new model. Reached for comment, Mazda spokesman Jacob Brown told Autoblog: "While we can confirm that Mazda continues to develop rotary engines, we cannot confirm production of a rotary at this point. Rotaries are one of the signature engineering technologies that define Mazda, and we will continue exploring them to see where they may fit for production applications." Related Video: