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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 CX-30 Luggage Test | How much cargo space?

The Mazda CX-30 is pretty much a lifted Mazda3 hatchback. Same platform, awfully similar dimensions, and the interior's a spitting image (if not identical). Ditto cargo capacity. On paper, the two have virtually the same amount of space behind their raised back seats, with the CX-30 at 20.2 cubic-feet and the 3 with just a teensy less at 20.1.  Now, before I go any further, let's see how much that 20.1 cubic-feet relates to in the Mazda3. I wasn't yet doing this test format back then, hence the video.  For reference, both tests used my standard luggage selection of two midsize roller suitcases that would need to be checked in at the airport (26 inches long, 16 wide, 11 deep), two roll-aboard suitcases that just barely fit in the overhead (24L x 15W x 10D), and one smaller roll-aboard that fits easily (23L x 15W x 10D). The bag of baseballs shown in the video is slightly smaller than my new small-bag go-to, my wife's fancy blue overnight bag (21L x 12W x 12D). So, the mark to beat is therefore all the bags minus the smallest roller.  Here is what 20.2 cubic feet looks like in the CX-30. To move beyond the Mazda3 comparison, that figure is in keeping with the CX-30's niche placement between subcompact (the teens) and compact SUVs (upper 20s to upper 30s). The Mazda CX-5 has 30.9 cubic-feet.  Now, typically, I start off by seeing how much I can fit inside with the cargo cover in place. Sadly, this particular CX-30's cargo cover is missing. We'll just have to hope it doesn't rob the CX-30 of as much space as the CX-5's does.  First off, it's immediately noticed that the CX-30's cargo area is not as long as the 3 hatchback's. The largest bag just barely squeezed inside, whereas there was some room to spare in the 3. Now, let's keep loading.  Whattya know? All of the roller bags fit inside. That includes the smallest one, which didn't fit in the 3, fitting atop the stack with perhaps 30% of it over the back seat line. Now, I could've done the same Tetris stack in the 3, but I'm virtually certain the hatch wouldn't have closed. Advantage, then, to the CX-30 and its extra height.  And surprise, the fancy bag also fits. Technically. It robs rear visibility, is pretty far above the seat line and it just barely fits under the back light. If it was filled, I have my doubts about its inclusion. Nevertheless, with or without it, there's still a bit more space on the right side for that bag of baseballs.  Now let's discuss the power liftgate.

Finalists for 2014 Green Car of the Year announced

The list of finalists for the 2014 Green Car of the Year has been announced, and in a genuinely bizarre twist, there's only one hybrid and no electric vehicles among the five contestants, despite the arrival of cars like the BMW i3 and Tesla Model S. Taking the place of the EVs are a pair of diesels, repping a technology that last won a Green Car of the Year award in 2009, when the Audi A3 TDI took the title. No diesel was in the running for last year's award.
Naturally, both of the diesel finalists are fielded by the Germans - with BMW's 328d and Audi's A6 TDI getting the nod. In the case of the 3 Series, BMW installed a 2.0-liter, turbodiesel, capable of delivering 180 horsepower and 280 pound-feet of torque, while returning 45 miles per gallon on the highway. Audi and its larger, 3.0-liter, V6 turbodiesel produce quite a bit more grunt, with 240 hp and 428 lb-ft of grunt, but net a very impressive 38 mpg on the highway in the A6.
Finalists for this year's awards include two diesels, three gas-powered cars and a plug-in hybrid.