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Toyota announces new, more efficient powertrains for 60 percent of its vehicles by 2021

In the face of increasingly strict standards on fuel economy and CO2 emissions, Toyota announced today that it's introducing a new hybrid system, a new 2.5-liter direct-injection inline four-cylinder engine, and two new transmissions – an eight- and a 10-speed. The development of all of these components will be based around the Toyota New Global Architecture, or TNGA. Development of the systems has moved forward and the new powertrains will find their way into vehicles starting next year. TNGA, like Mazda's Skyactiv technology, is a complete design philosophy that focuses on more than just a clean or efficient engine. The first vehicle to deploy the TNGA platform was the current, fourth-generation Prius. With TNGA, Toyota focused on improving handling, ride, and braking performance. The new powertrains are meant to compliment this new platform by being both engaging to drive and fuel efficient. Since TNGA can be adapted for front-, rear-, or all-wheel-drive layouts, it's capable of underpinning a number of potential products. Toyota is arguably the leader in hybrid technology, and taking lessons learned in the development of the current Prius, the automaker has developed the new Toyota Hybrid System II, or THS-II, for rear-wheel-drive applications. Performance has improved versus the outgoing model, and Toyota says efficiency, especially at high speeds, has been improved. In addition, the system's use in plug-in vehicles has been improved. For the first time, the electric motor will be able to provide direct driving power, whereas before it simply acted as a generator. The new, naturally aspirated 2.5-liter four-cylinder, like the THS-II, has been designed around the TNGA platform. Most notably, the thermal efficiency of the engine has been improved. This means a higher output and improved exhaust and cooling. The new engine, which works in both traditional and hybrid applications, will proliferate through the Toyota and Lexus lineup. Toyota's two new automatic transmissions, like the new engines, are based on the TNGA system. That means a lighter and more compact design relative to similar transmissions. The 10-speed is intended for rear-wheel-drive Lexus products like the GS and LS. The tuning has been adjusted to improve response and smooth out shifts, though it's impossible to say how much it's been improved without getting behind the wheel.

Mazda-Toyota partnership has us dreaming of a rotary hybrid

As you may have seen, Mazda and Toyota are going to be working a little more closely with each other. In their announcement, the two companies said they'd be building an American assembly plant together, and working on electric vehicle technology. But one of the companies' goals got our mental gears turning: It's listed as "Expand complementary products," and it's left very open-ended. The companies say they "will further explore the possibilities of other complementary products on a global level." These are in addition to Mazda providing the Mazda2 to Toyota as the Yaris iA, and Toyota providing Mazda a commercial van to sell in Japan. So what could these future complementary products be? We have a couple of ideas, one that's ludicrous but awesome (and, sadly, probably won't ever happen), and the other grounded in reality. Let's start with the fun one. What's the one thing Mazda fan has been wanting for years? A rotary sports car, of course! And while Mazda has repeatedly said that it has a small band of engineers plugging away at the spinning triangle problem, the odds of Mazda putting it into production have been slim. The inherent thirst of the rotary would make it tough to introduce when fuel economy regulations have been tightening. Plus, Mazda is a small company that needs to stretch every dollar, and having a one-off engine not based on anything else would be expensive. How could Mazda get around these obstacles? This is where the partnership with Toyota comes in, in our long-shot fantasy. Aside from having deep pockets, Toyota has a wealth of knowledge in the realm of hybrids. Thus, why not a rotary hybrid? Electrifying their oddball motor would fix two issues. One is obviously the fuel economy, since the gas engine wouldn't have to run all the time. The other is in providing torque. Rotaries infamously have little torque, especially down low, so adding an electric motor would allow this hypothetical rotary sports car to have a grunty low end, while still providing the Everest-high redline rotary fans like. The idea would be sweetened with the solid-state batteries that Toyota is developing, which could provide lots of electricity without weighing a ton. The rotary-electric mashup notion isn't totally alien to Mazda, either, since the company created an electric Mazda2 with a rotary engine for a range extender — albeit for different reasons. The company even filed a patent for the rotary range extender recently.

Toyota to buck engine downsizing trend, may go larger and turbo-free

Turbocharging isn't really Toyota's specialty, and the Japanese automaker isn't being shy about acknowledging it. Koei Saga, a senior managing officer in charge of drivetrain research and development, says that eschewing turbos and increasing displacement of engines using the Atkinson cycle can produce better power gains without sacrificing fuel economy, Automotive News reports.
Toyota is investing heavily in larger-displacement Atkinson-cycle engines in addition to turbocharged engines, but Saga doesn't think the automaker will use turbocharging across many product lines. He apparently remains unconvinced that the technology "makes the world better."
In Toyota's eyes then, Atkinson cycle engines do make the world better, and here's how. Their pistons complete four processes - intake, compression, power and exhaust - in one revolution of the crankshaft, and the power stroke is longer than the compression stroke. Traditional Otto cycle engines require two crankshaft revolutions to accomplish those same four operations and have equal-length compression and power strokes. Atkinson cycle engines are more efficient, but less power dense, though increasing displacement can offset that shortfall.