Toyota Develops TNGA-based Powertrain Units for Smooth, Responsive, As Desired Driving. New Engines and Transmissions and Improved Hybrid Systems Also Reduce Fuel Consumption and CO2 Emissions
- Fundamental vehicle performance thoroughly reviewed in pursuit of better driving performance and better environmental performance. Under "Direct & Smooth" developmental theme, challenge taken up to "change how Toyota cars drive".
- New powertrain units to feature in 60 percent or more of vehicles sold annually in Japan, United States, Europe and China in 2021, reducing CO2 emissions in those markets by 15 percent or more(1).
Using TNGA, Toyota has been changing the automobile from its very structure, lowering hood heights, lowering the center of gravity and implementing other innovations to improve driving performance. To enhance fundamental vehicle performance in terms of running, turning and stopping, it initiated a comprehensive review centered on vehicle platforms and is now, since the release of the fourth-generation Prius in 2015, expanding the use of new platforms throughout its product lineup. At the same time, it has been developing new powertrain units, which form the core of an automobile, that significantly improve both driving and environmental performance.
Toyota's newly developed powertrain units are light and compact and have a low-center of gravity. In-depth reconsideration of fundamental vehicle performance has resulted in engines with high-speed combustion and in highly efficient multi-geared transmissions. Furthermore, to standardize the basic structure of these new units, modular design (unified design) was used, building a foundation for the future making of "well-built cars".
While it was a given that the new powertrain units would be designed to have a high level of environmental performance, development focused on achieving driving performance that would "change how Toyota cars drive", under the theme "Direct & Smooth".
For Toyota, the starting point of making cars is "fun to drive" - the feeling of joy that comes when behind the wheel. Toyota aims to make cars with driving performance that responds to the will of the driver and are, at the same time, highly fuel efficient, among having other environment-friendly attributes. The new powertrain units announced today, in themselves, provide approximately 10 percent better power performance(2) and approximately 20 percent better fuel economy. Combining the new powertrain units with the overall evolution of the vehicle body, including aerodynamics, weight reduction and others, can open the way to even greater power performance and fuel economy.
New 2.5-liter Direct-injection, Inline 4-cylinder Gasoline Engine
Toyota has named its new line of internal-combustion power plants "Dynamic Force Engines". To bring out the new engines' potential to the fullest, their basic structure was completely rethought using TNGA, and their overall structure and configuration were wholly innovated to achieve high-level driving and environmental performance. Work will continue to make the new engines even more advanced.
The new engines employ high-speed combustion technology and a variable control system. They also achieve greater thermal efficiency, resulting in high output, due to a reduction in energy losses associated with, among others, exhaust and cooling systems and the movement of mechanical parts. Their lineup includes a 2.5-liter engine that has one of the world's best thermal efficiencies(3) - 40 percent when used in gasoline-powered vehicles and 41 percent when used in hybrid vehicles (HVs). This new, thoroughly reconsidered and greatly evolved engine features numerous new technologies, such as technologies for minute control that make it highly responsive and allow it to generate ample torque at all speeds.
New 8-speed and 10-speed Automatic Transmissions (Direct Shift-8AT & Direct Shift-10AT)
Toyota has developed two new automatic transmissions-the 8-speed Direct Shift-8AT and the 10-speed Direct shift-10AT. For both, various measures were taken to minimize energy loss and heighten transmission efficiency. Gear tooth surfaces were processed using a new technique for a lower coefficient of friction when the gears engage, and the configuration of the friction material used inside the clutch was optimized to reduce clutch torque loss by approximately 50 percent during rotation (compared to a conventional 6-speed transmission). These and other efforts resulted in achieving one of the world's best transmission efficiencies(3). The new automatic transmissions are more compact and lighter than comparative conventional transmissions, lowering a vehicle's fuel requirements. And their lower center of gravity results in both improved straight-driving stability and better cornering stability.
Furthermore, widened gears and a newly developed high-performance compact torque convertor combine for a broader gear lockup range. The resulting quick and smooth response to accelerator pedal operation creates an "as desired" direct driving feel.
In the case of the Direct Shift-10AT, even though the number of gears has been increased to 10 (compared to eight gears in the case of the Direct Shift-8AT), the use of close-ratio gears optimizes the range of use of each gear, particularly in the low-to-mid speed range. The resulting smooth gear changes, which are among the world's quickest(3), create a rhythmical and comfortable sensation that is suitable for a premium rear-wheel-drive vehicle.
Through such measures, fundamental vehicle performance in practical driving situations ranging from driving around town to driving on the highway has been improved to a degree that drivers can distinctly experience. Smooth response to accelerator pedal operation enables "as desired" vehicle departure and, in overtaking maneuvers, it allows lag-free and rhythmical acceleration that meets driver expectations, even in cases of sudden and heavy accelerator pedal use.
Advancement of Toyota Hybrid System II (THS-II)
Applying size-reducing, weight-reducing and loss-reducing technologies used in the fourth-generation Prius, Toyota has enhanced its hybrid system for 2.5-liter engines and developed the new, high-performance Multistage THS II for rear-wheel-drive vehicles.
THS II for 2.5-liter engines excels in both power and fuel-economy performance due to the synergistic effect of size-reducing, weight-reducing and loss-reducing technologies coupled with the high thermal efficiency and output of a new TNGA-based engine.
Multistage THS II gives hybrid vehicles an all-new driving image with its start-from-stop acceleration performance and abundant direct feel. In addition to improving system efficiency at high speeds, intermittent use of the engine at high speeds has also been made possible, further improving high-speed fuel economy.
The system for plugin hybrid vehicles (PHVs) has also been enhanced. A new dual-mode drive system allows the electric motor, which was hitherto used only as a generator, to provide direct driving power, resulting in powerful driving, even when in EV mode. Further enhancing the system for PHVs is a large-capacity lithium-ion battery that largely increases the EV-mode cruising range to 60 kilometers or more(4).
Roll-out of New Powertrain Units
Through TNGA-based car-making, efficiencies have been achieved in the development of the base technologies of the new powertrain units, along with improvements in quality, making possible the concerted release of affordable, high-quality products. This will lead to Toyota being able to quickly provide its customers with ever-better cars and to further promote widespread use of environment-friendly, fuel-efficient vehicles.
Within the five years to the end of 2021, Toyota plans to introduce 17 versions of nine engines, including the 2.5-liter engine announced today, 10 versions of four transmissions, including multi-geared automatic transmissions and a new kind of continuously variable transmission, and 10 versions of six hybrid systems.
In this way, through TNGA-based modular development, Toyota will roll out numerous types of new powertrain units within a short timeframe, successively introducing them in various vehicle models, starting with the launch of a new-model vehicle in 2017.
By the end of 2021, Toyota aims to have the new powertrain units feature in 60 percent or more of Toyota-brand and Lexus-brand vehicles sold annually in Japan, the United States, Europe and China. Toyota forecasts that Toyota and Lexus vehicles sold that year in those markets will account for a CO2 reduction in those markets of 15 percent or more, counting the fuel-efficiency-improvement contributions made by the new powertrain units alone.
Review and Strengthening of Development Structure of Powertrain Company
Toyota intends to review and strengthen the development structure of its in-house Powertrain Company. Conventional engine-powered vehicles account for the vast majority of vehicles currently on the market, and HVs and PHVs, the advance of which is expected to continue, also have internal-combustion engines. In addition to promoting development of engines and transmissions, which are seen to remain mainstay for some time to come, toward the coming electrification of vehicles, Toyota is accelerating its development of hybrid technologies (electrification technologies), such as those used in electric motors, batteries and power control units (PCUs).
1) Sharing technologies to raise the collective ability of the Toyota Group
Toyota has long conducted research and development of key technologies and systems based on its stance to "acquire through in-house creation". The accumulation of knowledge, know-how and experience is what allows Toyota to turn failure into improvements. This approach has been the backbone of Toyota research and development and is viewed as why Toyota was able to develop a practical hybrid system, launch the "Prius"-the world's first mass-production HV, and develop and be quick to market with the "Mirai" fuel cell vehicle (FCV).
However, Toyota realizes that it would be difficult to heighten the pace of development and commercialization of electrification technologies for further reducing CO2 emissions if Toyota addressed such as it has done until now, relying only on its own resources. Toyota will continue to carefully select that which it deems necessary to "acquire through in-house creation". But, from now on, it will also promote the sharing of technologies within the Toyota Group and increase the number of fields covered by joint research. It will strengthen joint development that uses cross-group obeya (project rooms with displays for sharing and reviewing goals, policies, timelines, progress and problems, etc.), efficiently use group resources to quickly establish advanced technologies and aim for increases in three areas: in the collective ability of the Toyota Group, in the speeding of development and in the scale of proliferation and expansion of environmental technologies.
2) Strengthening the development structure for hybrid technologies, which are core technologies for electrification
Key hybrid technologies, such as those found in electric motors, batteries and PCUs, are also key technologies used in vehicles that are powered by electricity, such as PHVs, FCVs and EVs. For the electrification of vehicles, to greatly accelerate the development of hybrid technologies, which Toyota positions as the core technologies of environmental technology development, Toyota plans to increase its number of hybrid technology-development personnel. Specifically, it plans to reorganize its development structure starting in 2017 and increase its number of people involved in hybrid technology development by approximately 30 percent within the five years to the end of 2021. Beyond then, as well, it plans to further strengthen its human resources for hybrid technology development as needed.
To contribute to the preservation of Earth's environment, Toyota is aiming to reduce new-vehicle CO2 emissions by 90 percent (compared to 2010 levels) by 2050. Based on its principle policy of conserving energy, which is the cornerstone of its development of environment-friendly technologies, by furthering the evolution of engines and transmissions and by promoting widespread use of HVs and PHVs, Toyota is endeavoring to improve fuel efficiency as a means of reducing CO2 emissions. And with a view to the future and an eye on limiting the consumption of fossil fuels centered on petroleum, to respond to the diversification of energy sources, Toyota is advancing its development of zero-emission vehicles, such as FCVs, which use hydrogen, and EVs.
To further reduce CO2 emissions, Toyota is continuing its development of environmental technologies and its commercialization of environment-friendly vehicles from the perspective that environmental contributions cannot be achieved without widespread use of environment-friendly vehicles.
Going forward, through TNGA-based ever-better car-making, to accelerate the commercialization of ever-better cars that are both fun to drive and that contribute to Earth's environment and to accelerate the reduction of CO2 emissions, Toyota will strengthen its undertakings by rallying the collective ability of the Toyota Group.
(1) Comparison of average amount of CO2 emitted by Toyota and Lexus vehicles actually sold in 2015 in Japan, United States, Europe and China and average amount of CO2 emitted by Toyota and Lexus vehicles planned to be sold in 2021 in Japan, United States, Europe and China, including vehicles equipped with newly developed powertrain units
Estimated CO2-reduction contribution made only by newly developed powertrain units based on certified data in each country or region
(2) In terms of time needed for a gasoline-powered vehicle to accelerate from 0 miles per hour to 60 miles per hour and for a hybrid vehicle to accelerate from 40km/h to 70km/h
(3) As of November 2016, according to Toyota survey
(4) Developmental target value (in the JC08 test cycle); measured by Toyota
Supported by people around the world, Toyota Motor Corporation (TSE: 7203; NYSE: TM), has endeavored since its establishment in 1937 to serve society by creating better products. As of the end of December 2013, Toyota conducts its business worldwide with 52 overseas manufacturing companies in 27 countries and regions. Toyota's vehicles are sold in more than 170 countries and regions. For more information, please visit www.toyota-global.com.
Toyota Motor Corporation Public Affairs Division Global Communications Department Tel: +81-3-3817-9926
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