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Increasingly stringent environmental regulations requiring lower CO2 emissions and higher fuel economy have made it essential to develop vehicles with superior fuel efficiency and cleaner emissions. At the same time, there is growing demand for even more powerful and quieter vehicles. To help satisfy these requirements, Toyota Motor Corporation has developed a new 8-speed automatic transmission for front wheel drive vehicles, incorporating its first compact torque converter with a multiple disk lock-up mechanism. This newly developed compact torque converter with a multiple disk lock-up mechanism was designed under the Toyota New Global Architecture (TNGA) development concept to achieve an excellent balance between higher efficiency through the commonization of components and stronger product appeal through installation on a whole family of transmissions. This compact torque converter is compatible with a variety of engines from inline 4-cylinder to V6 configurations.

In response to global demands for environmental conservation, the automotive industry is placing greater focus on the development of fuel-efficient technologies to help reduce global CO2 emissions. With the aim of simultaneously improving fuel economy and driveability, TOYOTA has developed a new continuously variable transmission (CVT) vehicles in North America equipped with a 1.8-liter engine [1]. This new CVT features various technologies for improving fuel economy, including: the world's first coaxial 2-discharge port oil pump system, wider ratio coverage, a flex start system, low-viscosity CVT fluid, and a higher final gear ratio. This paper outlines the configuration, characteristics, performance, and new technologies of this CVT.

Toyota Motor Corporation has developed a new 6-speed automatic transmission (U660E) for the front-wheel drive vehicles and large displacement engines. The U660 E was adapted to achieve improved environmental protection, and meet safety standards, which are large concerns for the society and customer satisfaction, by being small, light, highly efficient, quick response, and high shift quality. Toyota fundamentally improved both the hardware and software of the control system to meet these important goals.

A new compact five-speed automatic transmission (A650E) has been developed for front engine rear wheel drive cars. The development of this transmission has been aimed at improving fuel consumption, power performance, engine noise reduction during highway cruising and smooth acceleration by employing a wide range of gearing and close gear ratios. Generally a five-speed automatic transmission is larger than a four-speed, because of additional friction elements and gears. This can result in a change in the floor panel of the car body. However, by removing a one-way clutch for second gear and employing a unique gear-train layout, this transmission has the same circumference and length as the conventional four-speed automatic transmission (A340E)(1).1 In order to reduce first or second gear noise, gear specification and supporting structures of planetary gears have been optimized by FEM analysis.