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Mazda patents show rotary engine for range-extended EV

Two years ago, Mazda introduced a fascinating range-extended electric car called the Mazda2 RE Range-Extender. It took an electric Mazda2, and dropped in an itty-bitty 330cc rotary engine. It wasn't the rotary-powered sports car we had hoped for, but it seemed like a unique way to keep the quirky engine alive and kicking. But not long after the car's reveal, it seemed to disappear. Now the basic idea has resurfaced with a few modern updates in a couple of US patents. The first patent is pretty straightforward and describes a range-extended EV similar to the BMW i3. At the front is an electric motor driving the front wheels. At the back is an internal combustion engine that powers an electric generator. In the middle is a lithium-ion battery for storing and delivering electricity. It's the same set-up as that Mazda2. The second patent is for an engine start-and-stop system, but specifically for rotary engines. The system is designed to shut off a rotary engine when not needed, much as modern piston engines do. It also stops the rotor in a position that closes the intake port to ensure no fuel or exhaust emissions slip out through the intake tract. This is necessary since there are no valves in a rotary, and air and exhaust come through ports that are "opened" and "closed" by the rotor itself. The patent also describes the possibility of firing a spark plug after the fuel has been cut to eliminate any leftover fuel emissions. This system would theoretically improve a rotary engine's fuel economy and emissions significantly, which would be a boon as those are two of the rotary's major weaknesses. The rotary-engine patent also includes the same range-extended powertrain drawing as the first patent. It's there as a description of a possible application. And in such an application, where the rotary wouldn't have to run all the time, the system could take advantage of the rotary's inherent strengths. Weight can be kept low thanks to the engine's small dimensions, which should help in keeping the car sprightly and efficient. Rotaries are renowned for smoothness, too, so it shouldn't need too much refining and sound deadening, the latter of which adds more weight. The small size would also help with packaging, leaving more space for people, cargo, or possibly batteries. And since it has been patented, the company may be looking to bring the system to market.

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:

2014 Mazda CX-5 with 2.5-liter Skyactiv engine

Back in October, we compared the relative merits of two new and very good small crossovers: the 2013 Ford Escape and 2013 Mazda CX-5. The CX-5 we tested then had Mazda's 2.0-liter Skyactiv-G engine under its hood, and it managed to just edge out the EcoBoosted Ford despite being down by some 23 horsepower and 34 pound-feet of torque. Had it been available, the 2.5-liter Skyactiv engine that we recently had the opportunity to try out in the 2014 Mazda CX-5, it may have made that comparison even easier to call in the Japanese CUV's favor.
Clearly, if you're in the market for a reasonably sized crossover, the CX-5 should, at the very least, be on your test-drive list. The new engine offering will let buyers opt for a stronger powerplant, with 184 hp and 185 lb-ft on tap. On our second day in Austin's Hill Country - the first was spent quick-spinning the 2014 Mazda6 i Sport, you'll recall - we covered a couple of hundred miles and put the new CX-5 through its paces; here's what we turned up.
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