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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.

Mazda2 sedan debuting in Thailand this month?

Mazda is reportedly set to introduce a Mazda2 with a four-door sedan body. Unlike the upcoming CX-3, which is debuting at the upcoming Los Angeles Auto Show and is almost certain to be sold in North America, this other version's chance here are a bit more mysterious.
According to The Bangkok Post, the Mazda2 sedan will make its word debut at the Thailand International Motor Expo on November 28, and the traditional five-door hatch will be there as well. Both body styles will be built in Thailand with diesel engines and will be the first vehicles to adhere to the country's eco-car rules for oil-burners with a SkyActiv 1.5-liter diesel that will make 105 horsepower.
At this time, there's no indication whether the new sedan might also be sold in the US, but we're not holding our breath - remember, the previous Mazda2 sedan never made it Stateside, either.

Honda, Mazda, Mitsubishi, Mercedes also under diesel emissions scrutiny

The controversy over Volkswagen's diesel emissions scandal isn't limited to the US. In Europe, where diesel engines are far more popular, the issue is shining a harsh light on the NEDC emissions test. As already known, the evaluation does a poor job of reflecting real-world production of NOx, and it appears a significant number of automakers are affected. The Guardian in the UK has been reporting on real-world test results from a company called Emissions Analytics. After the latest round of checks, vehicles from Mercedes-Benz, Honda, Mazda and Mitsubishi were found to generate far more NOx than they should. The newspaper also published similar results for Renault, Nissan, Hyundai, Fiat, Volvo, Jeep, Citroen, VW, and Audi. On average, the figures are about four times over the limit of producing the pollutant. Unlike VW and its defeat device, these automakers aren't actually breaking the rules. The vehicles perform up to the NEDC lab test for emissions, but those results simply aren't translated to the street. "The VW issue in the US was purely the trigger which threw light on a slightly different problem in the EU - widespread legal over-emissions," Nick Molden from Emissions Analytics said to The Guardian. A big fight to decide the future of this issue appears to be on the horizon. Automakers claim that they can't meet the next round of tightening emissions regulations and are asking for compromises. Although, spokespeople for Mercedes and Honda told The Guardian that the brands would be in favor of the stricter rules. Meanwhile, some European governments began backtracking their support of diesels well before this scandal came to light. The added scrutiny certain hasn't helped the future of the oil-burner. Related Video: