2003 Mazda Miata Se Convertible 2-door 1.8l on 2040-cars

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Fourth-gen Mazda MX-5 Miata could get turbo power later in life

While there's a lot to love about the new Mazda MX-5 Miata, its debut was met by a vocal group of enthusiasts who derided the fourth-generation roadster's reduction in power output. The new model only puts out 155 horsepower, down from 167 in the NC. A report from Australia, though, claims Mazda may yet address the less potent output of the ND. Things started earlier this year, as Motoring.com.au tells it, when Mazda's global PR boss, Kudo Hidetoshi, hinted that a turbocharged or Mazdaspeed model "will definitely" be considered. Then last month at Goodwood, the ND's program manager, Nobuhiro Yamamoto, said complainers were welcome to get their thrills elsewhere. Recognizing this contradiction among Mazda's brass, Motoring asked Yamamoto-san again about his statements, which he seemed to walk back. "It's not a conflict [between statements made by Yamamoto and Hidetoshi]," Yamamoto said, indicating that his statements were made in relation to the new MX-5's launch. "Kudo-san talked about this in terms of a 10-year lifespan, but when I was asked the question right after the launching of the ND, I said 'we have no plan to have a turbo at that point in time.' That is what I meant." Seeking an opening, Motoring pushed the Japanese engineer on the chances of a more potent MX-5, perhaps without a turbocharger. "If you could achieve what we want, to which is great response, very light and powerful with great performance feel with natural aspiration, then we don't need a turbo," Yamamoto said. "But if we want more power because we don't get satisfied with natural aspiration then we may think about the turbo." Related Video:

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 next-gen SkyActiv engines will drop spark plugs in favor of high compression

Homogeneous charge compression ignition, or HCCI, is the black art of internal combustion engines that aims to produce diesel-like fuel efficiency for the cost of gasoline. Although some of its competitors have developed and subsequently given up on the tech, Mazda confirmed that the next-generation of SkyActiv engines will employ HCCI technology, improving fuel economy by 30 percent and at the same time reducing exhaust emissions. According to Nikkei, a new SkyActiv family of engines is set to debut under the hood of the next-gen Mazda3 sometime in 2018 before making its way into other vehicles. In simple terms, an engine that uses HCCI burns the air/fuel mix using pressure instead of with spark plugs, just like a diesel. At 14:1, Mazda's gasoline engines already have some of the highest compression ratios out there, but a move to HCCI means cranking up the compression to 18:1. While the tech sounds relatively straightforward, using HCCI means dealing with a number of side issues. It's one of those "on paper" ideas that compounds problems when put into practice. Heat, revs, and fuel must all be carefully managed as gasoline doesn't burn the same way as diesel. Mazda is mum on details, but the automaker seems confident that the issues have been sorted. If the new engines do indeed make it to market with HCCI, Mazda will have out-engineered GM, Daimler, and Hyundai, all of which have tried and failed to develop HCCI engines in a cost-effective package. With the market moving towards electrification, it's interesting to see Mazda still focusing so heavily on traditional internal combustion gasoline engines. It's an indication of where they see the market heading for the next few years. Although the automaker has been hesitant to move forward with hybrid and electric powertrains, Nikkei also reports that Mazda will begin mass production of EVs in 2019. Related Video: