Toyota Readies Next-Gen Powertrains, Hybrid Systems

Over the next five years, Toyota plans to introduce 17 versions of nine engines, 10 versions of four transmissions and 10 versions of six hybrid systems.

The new powertrains are expected to be fitted in at least 60% of the Toyota and Lexus vehicles sold annually in China, Europe, Japan and the U.S. by the end of 2021, according to the carmaker. It expects the systems to provide a 15% reduction in carbon dioxide emissions over today’s levels.

Toyota estimates the powertrains will boost fuel efficiency by 20% while providing a 10% improvement in acceleration performance.

The engines, transmissions and hybrid modules are designed for use in vehicles based on the Toyota New Global Architecture. The modular platform, which debuted last year with the fourth-generation Prius hybrid car, can accommodate front-, rear- and all-wheel-drive layouts covering a range of vehicle types and sizes.

The powertrain offensive kicks off next year with a 2.5-liter direct-injection 4-cylinder engine, a multi-stage version of the Toyota Hybrid System-II, and 8- and 10-speed automatic transmissions. Toyota describes all of them as lighter, smaller, more efficient and providing better driving dynamics than its current offerings. The products also are designed to sit lower in the vehicle to help lower the center of gravity and improve vehicle dynamics.

The naturally aspirated 2.5-liter engine will be used in a variety of Toyota and Lexus vehicles, including future hybrid models. Toyota says the engine’s 40% thermal efficiency is one of the best in the industry. Other highlights include a high-speed combustion technology and a variable control system.

The new direct-shift 8- and 10-speed transmissions will replace several 6-speed and continuously variable transmissions. The 8-speed system will be used for fwd models, while the 10-speed is for rwd applications.

Toyota says the transmissions provide faster and smoother shifts, thanks to wide gearing and a high-performance compact torque convertor. A new friction material and other updates cut rotational clutch torque loss in half, according to the carmaker. The 10-speed employs a close-ratio gear design to further improvement refinement.

The Multistage THS-II hybrid gearbox also targets rwd vehicles. The system features an electric motor integrated with a CVT and a conventional torque converter to optimize efficiency and sportiness. Toyota says the benefits are most noticeable during high-speed driving and startup launch.

The carmaker also cites improvements to its base THS-II system, which was introduced last year on the Prius, for applications with 2.5-liter engines. The system's use in plug-in vehicles has been improved by giving the electric motor the ability to provide direct driving power in addition to its role as a generator.

Toyota expects hybrid vehicles will account for 20% of its global sales by 2025, doubling the current rate. To support the growth, Toyota plans to reorganize its research and development organization next year and expand the number of people devoted to hybrid technology by 30% within five years.