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.
In the next five years, Toyota plans to release 17 versions of nine engines, including the new 2.5-liter four-cylinder. Since TNGA is an adaptable platform, the roll out will be eased through the use of shared components. By 2021, Toyota plans to have new powertrains in 60 percent of the vehicles sold in Japan, the United States, Europe, and China. In addition, the company seems to be backing down from fuel cell development in order to shift focus to battery electric vehicles.