1994 Mazda Miata M Edition Convertible 2-door 1.8l on 2040-cars

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Mazda2 with extended-range hybrid rotary tech shown

Every story dealing with a new rotary engine from Mazda lands in a different place on the matrix of possibilities between "Coming soon!" and "Never gonna happen!" In 2011 it was speculated that the rotary engineering program would be shut down with the demise of the RX-8, in 2012 the program was still alive and taking lessons from the SkyActiv engines, in August 2013 a Mazda insider said a rotary engine called 16X would be here in two years, in November the CEO said the only way we'd ever get a new rotary is if Mazda could sell 100,000 of them per year. Meaning that, for the moment, you can forget about it.
And yet, last month Mazda was putting journalists in a Mazda2 RE Range Extender, an electric car using a 0.33-liter rotary to power its lithium-ion batteries when the charge runs down. With a 75-kilowatt, 100-horsepower electric motor turning the front wheels, the Wankel generator and its 2.6-gallon gas tank living under the trunk double the range of the electric-only Mazda2 to 250 miles.
There's been talk of using a rotary to assist an alt-fuel vehicle for at least seven years, with Mazda pairing an electric motor with a rotary that ran on gas and hydrogen in a Mazda5 in 2007. Since then, almost all of those stories debating its return or demise also spoke of the oddball motor's advantages, such as compact size and ability to run on various fuels, as an aid in an unconventional powertrain.

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.

Aussie Mazda MX-5 Miata specs leak suggests power loss

Mazda's 2016 MX-5 Miata reveal didn't include much in the way of specifications, but the car's debut seems to have blown the lid off of the rumormill, with the latest word out of Australia including fresh claims of curb weight and engine output.
Before delving into the findings from Motoring.com, we're going to take a moment to find a few grains of salt. It's not that we don't trust the Oz publication, it's just that we wouldn't be surprised to learn their car's specifications will vary from that of our eventual North American car.
Of course, we don't expect the footprint of the new ND model to itself to differ much - it will still be the most compact Miata ever - overall length is expected to check in at just over 154 inches - that's about 1.4 inches shorter than the original NA Miata and over 4 inches shorter than today's NC generation, yet it'll ride atop a longer wheelbase and be slightly wider while sitting lower to the ground.