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Mazda3 to showcase CNG, Hybrid versions in Tokyo

Mazda has made huge gains in its competitive set with the introduction of its Skyactiv technologies, and the Japanese automaker appears to have no plans on slowing down. While we're still waiting for the Mazda6 Skyactiv-D diesel to go on sale in the US, Mazda announced that it will debut new Skyactiv-Hybrid and Skyactiv-CNG versions of the Mazda3 (standard US-spec model shown above) at next month's Tokyo Motor Show.
Matching up with what we heard earlier in the summer, the Mazda3 Skyactiv-Hybrid is intended for Japan only, but there are no details about this system regarding fuel economy, electric components or specs. Likewise, there are no details for the Mazda3 Skyactiv-CNG Concept, which is a bi-fuel version of the car running on both gasoline and compressed natural gas. As this car's name suggests, the CNG model is a concept vehicle, and there is no indication that Mazda plans offering such a model here in the US.
In addition to these two vehicles, Mazda will also have an Atenza (Mazda6) on display showing off some vehicle-to-vehicle (V2V) safety systems, called the ASV-5 (Advanced Safety Vehicle). Scroll down for Mazda's official press release.

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.

What a 181-horsepower 2019 Mazda MX-5 Miata means for us, and you

Last month, we reported on a VIN filing dug up by Road & Track that showed that the 2019 Mazda MX-5 Miata's 2.0-liter Skyactiv-G engine would get a power bump, from 155 to 181 net horsepower. As for how the 2019 Miata would make that extra power, we heard rumors it'd utilize a new cylinder head allowing higher revs, accounting for that extra power. Now we have what appears to be a leaked document from Mazda Canada showing exactly where that extra power comes from. According to the document posted at Miata.net (registration required to see the image), Mazda will alter camshaft lift and valve size on both the intake and exhaust side, fit freer-flowing exhaust, and smooth and enlarge the piping on the air intake side. There are also internal engine modifications: lighter pistons with lower crowns for better swirl in the combustion chamber, lighter connecting rods, and a crankshaft balanced for higher-RPM operation. All those extra revs mean extra vibration and noise, so Mazda will ditch the single-mass flywheel for a "low-inertia" dual-mass flywheel – which will attempt to find a nice balance between DMF damping action and SMF directness. Overall, it's a pretty serious engine revision with some driveline changes that will heavily affect the driving characteristics of a fantastic driver's car. Contributing Editor James Riswick and Senior Editor Alex Kierstein, both well versed in Miatas past and present, are here to analyze what this could mean for the little roadster. James Riswick: I don't know much about them lighter crank combustion rods, but I for one welcome the news of more power to the Miata. The jump from 155 to 181 seems like a very prudent Mazda-like thing to do, accomplishing that task through various aforementioned technical wizardry as opposed to slapping on a turbocharger, exclaiming "yee-hah" and calling it a day. Alex Kierstein: That's true. I'm wary of additional power, but you do make a good point that at least this is the right way to do it. Going all-motor will keep the bright responsiveness of the engine intact. But higher revs might make power delivery peakier. Frankly, I'd be ok with moving the torque and horsepower peaks up a bit in the rev range, making it a bit more work to access the engine's sweet spot. The dual-mass flywheel should also help if low-end torque suffers, so less stalling in traffic. JR: Did wonders in the 911 and 718s.