1997 Mazda Miata M Edition Convertible 2-door 1.8l on 2040-cars

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Mazda files patents for a sequential twin-turbo setup

Mazda has a history of interesting engine technologies, from yesterday's rotary engine to tomorrow's compression ignition engine, and new patents show it still may have some internal combustion tricks up its sleeve. The one on display in these patents isn't especially new in concept, though. A sequential twin-turbocharger setup is something Mazda itself used on the third-generation RX-7. But it's something we haven't seen much of lately. It looks like it could have some possible advantages over older sequential systems, and it has some potential advantages for enthusiasts. First a quick and dirty primer for what makes a sequential twin-turbo system distinct from other twin-turbo systems. In many twin-turbo engines, there are simply two turbos that work together as one bigger turbo. They're the same size, and they spool up at the same time. With a sequential setup, at low rpm, a smaller turbocharger is spooled up first at low-rpm for quicker throttle response, and as the rpm and exhaust pressure increases, a valve opens up that allows a larger turbocharger to also spool up and provide high-rpm boost. That's basically how the Mazda design shown above functions. A big flap blocks off the larger turbocharger exhaust inlet, channeling all the exhaust to the smaller turbo. When more exhaust is available at high rpm, it looks like that flap opens up to spool up the big turbo, too. What's interesting here is that the way the turbochargers are packaged takes up less space than past systems. It looks like both turbos are contained in one unit that shares the same exhaust outlet, meaning the exhaust manifold could be kept simple and compact. In fact, the piping for compressed intake air could also be shared, reducing the amount of piping, which would further decrease the amount of materials and possible failure points. There are a number advantages of making this system smaller. The potential applications of the system are much greater, since it could fit in smaller cars with smaller engine bays. Making the system smaller also means that there won't be as much weight, which is important from both fuel economy and performance standpoints. Finally, the smaller setup likely uses fewer materials, which could make the system cheaper and thus easier to offer on a wider range of vehicles, or at least more profitable for Mazda.

Why Mazda’s Skyactiv-X compression-ignition engine is a smart hedge bet

Mazda has cracked the code on a compression-ignition engine, called Skyactiv-X (which utilizes SCCI, or Spark Controlled Compression Ignition). That's a neat engineering accomplishment, sure, but why is the tiny company investing big dollars in fancy tech that's frustrated the much larger companies who've investigated it? In this case, Mazda is peering into a crystal ball to consider how best to flow with a few troubling tides. One is the premature handwringing about the death of the internal combustion engine, another is Europe's swing away from diesel engines. Skyactiv-X seems, at this juncture, a hedge bet against both aspects. EV infrastructure lags massively behind our petroleum infrastructure — no shock there. Mazda claims the tech will net 20-30 percent gains in fuel efficiency over its current gasoline engines and about matching its diesel engine. And that's without any onboard hybrid tech, so that staves off the inevitable necessity to fully adopt electrification for a while — this is assuming that, at some point, it won't be practical to sell a non-hybrid or non-EV. At what date that happens is open to debate, but as I said above, technology like this kicks that decision point down the road a bit. Mazda is here translating research dollars into time, allowing its engine factories a few more years of probably profitable production of internal-combustion engines before retooling, and before somebody needs to pour a massive amount of money into a broad EV charging infrastructure to replace gas stations. None of this is happening fast enough for a wholesale transition to EVs anytime soon. So, that's one bet hedged. The next is Europe's declining interest in diesel engines for mainly health reasons. Just about a week ago, The New York Times posted an excellent primer on this issue, which is somewhat controversial in Europe. Germany's auto industry, a huge portion of its economy, is heavily invested in diesel tech and seriously opposed to proposals in Britain and France to eliminate the technology, which creates unhealthy diesel particulate emissions. The German industry is hoping Band-Aids like pollution-reducing measures will help them, but after a massive and widespread emission cheating scandal, its credibility is at a nadir. It seems like consumers have sensed which way the wind is blowing, and it has hurt sales. The NYT reports that diesel sales in Germany alone — remember, bastion and originator of diesel technology — are down 13 percent.

2014 Mazda3 officially rated at 30/41 mpg, priced from $16,945*

It's hard not to be smitten with the 2014 Mazda3; after all, just look at it. But beyond its slick lines, we found the new compact hatch to be a pretty remarkable steer, offering up good levels of comfort and refinement, not to mention functionality and engagement. Now, there's more reason to like the 2014 Mazda3, as we've just learned that the car will officially be rated at 30 miles per gallon city and 41 mpg highway.
That 30/41 rating is for the Mazda3 sedan fitted with the 2.0-liter Skyactiv-G inline four-cylinder engine and a six-speed automatic transmission. Opting for the manual transmission retains the 41-mpg highway number, but drops the city digits to 29. Hatchback models with the 2.0-liter engine achieve 29/40 mpg with the manual 'box and 30/40 with the automatic.
Mazda also offers a larger 2.5-liter inline-four in the 3, and while a six-speed automatic will be the only transmission available with this engine at launch, the automaker has confirmed that a manual is coming shortly. With the 6AT and 2.5, the Mazda3 sedan is rated at 28/39 mpg, or 29/40 with the company's i-Eloop regenerative braking system. Hatchback models shrink those numbers to 28/37 and 29/39 mpg, with and without i-Eloop, respectively.