2014 Mazda Miata Mx-5 Club on 2040-cars

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How Mazda got Skyactiv-X to work is incredible

"Take everything you know about engines and turn it around," Mazda North America Vehicle Development Engineer Dave Coleman says, patiently and with a look of benevolent pity, as he's quizzed about the particulars of the company's new engine. The Skyactiv-X engine is enigmatic — and deceptively simple in operation. And the bottom line for American consumers is that they'll be able to buy a car (or crossover; we don't know yet what vehicle will first get it) by late 2019 that provides diesel-like fuel economy but runs on regular old gasoline. In between diesel and spark ignition, but it's neither To truly understand it, you have to dive into the contradictions. Take that regular old gasoline: Contrary to common sense, the lower the octane, the better it works. In the lab, the Skyactiv-X engine loves 80 octane. The lowest Americans get is 87, so the engine is tuned for that octane. Go higher and you lose some low-end torque. Coleman was right. It's hard to wrap your head around an engine that thrives just at the point when most gas engines would aggressively self-destruct. It uses a supercharger to pump additional air — but not additional fuel. It uses spark plugs to start a combustion cycle that normally doesn't need a spark. And, quixotically, it's not displacing Mazda's own American-market diesel engine, currently languishing in a seemingly endless hell of regulatory approval. More bizarre: Mazda is a tiny automaker facing real existential headwinds, and gasoline compression ignition is a massive challenge. GM and Hyundai announced compression ignition, or HCCI, projects (full name, homogeneous charge compression ignition) to great fanfare, but they never amounted to a production hill of beans, crippled by reliability issues or horrible vibrations. Worse, they only worked at an unusably narrow range — low RPMs and low loads. HCCI research improved direct-injection gas and diesel engine technologies for these companies, but HCCI itself remains untamed. The benefits of lean combustion Why even try to tame HCCI? The answer is much better fuel economy and lower emissions. Less burned carbon-based fuel, less carbon dioxide released. That's simple. But there are some thermodynamic reasons for the lean combustion you can achieve with compression ignition that are worth explaining. The ideal amount of fuel for a conventional engine to burn is about a 14:1 air-to-fuel ratio. That lets every molecule burn nicely, in theory.

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:

Will the Mazda2 be offered as a PHEV with a rotary engine range extender?

Every few months, it seems a rumor crops up about plans from Mazda to revive the rotary engine. Last November, its CEO said the only way another one could happen is if the project was profitable, and then a month later the automaker showed off the Mazda2 RE Range Extender with a 330cc Wankel engine mounted in the rear. Now, Australian auto site Motoring reports that the PHEV may actually make production in the next-gen Mazda2 sometime after it's initial launch.
Martin Benders, managing director of Mazda in Australia, spoke to Motoring about the company's future with hybrids and basically reiterated what the CEO said last year. The Japanese automaker only plans to offer electrified powertrains in places where they can sell in sufficient numbers to be profitable, like Japan.
Mazda has been playing with the rotary range-extender idea for years. In the RE prototype, the engine was exclusively used to charge the lithium-ion batteries when they were running low, and a 100-horsepower electric motor provided all of the propulsion. It gave the little hatch an estimated range of about 250 miles. The company reportedly took inspiration from its Skyactiv engines to make the Wankel have lower friction and a lighter weight.