Toyota New Global Architecture -TNGA

Toyota Motor Corporation, in pursuit of superb driving and environmental performance, and based on the Toyota New Global Architecture (TNGA) structural reform for making ever-better cars, has developed advanced engines and transmissions and further evolved its hybrid systems. Toyota intends to deploy these new powertrain units in a rapidly broadening range of vehicle models, starting in 2017.

Toyota Motor Corporation (Toyota) announces that it has developed a new continuously variable transmission (CVT), 6-speed manual transmission, 2.0-liter engine, 2.0-liter hybrid system, and 4WD systems based on the Toyota New Global Architecture (TNGA), a development framework aimed at making ever-better cars. The new technologies offer both superb driving performance and high environmental performance.

2019 Toyota New Engine and CVT Transmission for 2.0-liter Class Based on TNGA

Direct Shift-CVT: A New Type of Continuously Variable Transmission

The basic function of any transmission system is to achieve transmission efficiency, high-efficiency engine ranges, and highly responsive gear changes. To improve these functions, Toyota has striven to reduce mechanical loss, adopt a wider gear range, and improve shift tracking. These initiatives have resulted in a direct and smooth driving experience with superior fuel efficiency, which has been improved by six percent over the existing transmission system.

Reduced mechanical loss

The new powertrain unit features the world's first launch gear in a passenger vehicle CVT1, which facilitates improved transmission efficiency in lower gear ratios where belt efficiency is poor. The transmission system utilizes gear drive when starting from a full stop, resulting in powerful acceleration while at the same time resolving the momentary sluggish feeling that was previously present during accelerator operation. Both smooth and comfortable launch performance are realized. When switching from gear drive to belt drive, the transmission system uses highly responsive gear change control technologies cultivated from AT technology.

Conversion to wider gear ranges

In line with the adoption of a launch gear, belt use is now specified for higher gear ratios. This new setup not only improves the efficiency of belt use, but also enables the adoption of wider gear ranges, thereby realizing a class-leading gear ratio range of 7.5 for the 2.0-liter class1.

Improved shift tracking

The adoption of launch gears results in reduced input load. This enables the size of both belt and pulley components to be reduced. The belt angle has been narrowed and pulley diameters reduced, resulting in shifting speeds that are 20 percent faster. Both powerful and rhythmic acceleration are realized.

New 6-speed Manual Transmission (6MT)

Toyota has also developed a new manual transmission in response to global needs, particularly those in Europe. Compared to the existing version, the mass of the new system has been reduced by seven kilograms and total length by 24 millimeters. This makes it one of the world's smallest transmissions1, and its small size contributes to improved fuel efficiency. The 6MT also offers world-leading transmission efficiency1, while the use of iMT (Intelligent Manual Transmission) controls, which automatically adjust engine rotations when changing gears, ensures smooth gear shifting―free of uncomfortable recoils―for the driver.

2.0-liter Dynamic Force Engine, a New 2.0-liter Direct-injection, Inline 4-cylinder Gasoline Engine

Toyota's new Dynamic Force Engine adopts high-speed combustion technologies and a variable control system. It also achieves greater thermal efficiency, resulting in high output, due to a reduction in energy loss associated with exhaust and cooling systems, the movement of mechanical parts, and other aspects. As a result, the newly developed 2.0-liter gasoline vehicle and hybrid vehicle engines achieve world-leading thermal efficiencies of 40 percent and 41 percent respectively1. In addition, compared to existing engines, the new engines achieve increased torque at all engine speeds―from low to high rotations―and will comply with expected future exhaust regulations in each country in advance.

2.0-liter Toyota Hybrid System (THS II)

Toyota has developed a new hybrid system for 2.0-liter engines, which applies the same size-reducing, weight-reducing, and loss-reducing technologies used in the fourth-generation Prius. The new system realizes improved driving performance while retaining superior fuel efficiency. When accelerating, the hybrid system reduces engine rotations while drawing increased electric power from the battery, thereby delivering a linear and lengthened sense of acceleration.

New Dynamic Torque Vectoring AWD and E-Four 4WD Systems

Toyota has developed two new 4WD systems with the aim of improving fuel efficiency and achieving high 4WD handling, stability, and off-road performance.

The new Dynamic Torque Vectoring AWD system is used in gasoline engine vehicles. By adopting a torque vectoring mechanism, which independently distributes torque to the left and right rear wheels according to driving conditions, the Dynamic Torque Vectoring AWD system enables the driver to steer the vehicle exactly as intended. It achieves high off-road performance even on the toughest roads. It also incorporates a disconnect mechanism, which features the world's first ratchet-type dog clutches1 on both the front and rear wheel shafts. These clutches stop the drive system rotations, which transmit driving force to rear wheels when in 2WD mode, significantly reducing energy loss and improving fuel efficiency.

1. CVT Transmission Toyota
2. Dynamic Force Engine
3. Toyota Hybrid System 2

Direct Shift-CVT: A New Type of Continuously Variable Transmission

The basic function of any transmission system is to achieve transmission efficiency, high-efficiency engine ranges, and highly responsive gear changes. To improve these functions, Toyota has striven to reduce mechanical loss, adopt a wider gear range, and improve shift tracking. These initiatives have resulted in a direct and smooth driving experience with superior fuel efficiency, which has been improved by six percent over the existing transmission system.

Performance

High transmission efficiency and enhanced fuel economy
Realization of best-in-class* shift speed ratio spread and a 6% improvement in fuel efficiency.
*As of February 2018 (Toyota Motor Corporation)

Direct and quick response

Shift performance equal or greater than DCTs produced by other companies.

Details of new technologies

Launch gear

By adopting launch gears, it is possible to improve belt efficiency and increase ratio spread by 15% without performance deterioration.

Narrow belt angle

Shift speed is improved with a reduction of the belt angle from 11 degrees to 9 degrees. (shift speed increase of 20%)

More compact pulley

The adoption of launch gears reduces the belt load. Shift responsiveness has improved through downsizing of the pulley and reduction of inertia by 40%.

New TNGA Dynamic Force 2.0L engine

At the New York International Auto Show this week, Toyota will stage the premiere of the new 2019 Corolla Hatchback. The all-new TNGA-based powertrain features the 2.0-liter Dynamic-Force direct-injection inline four-cylinder engine (M20A-FKS) (earlier post) with gains in power, fuel efficiency, and cleaner emissions.

Physically, the engine is smaller and lighter than its 1.8-liter four-cylinder predecessor, which helps to lower Corolla Hatchback’s center of gravity and benefits its overall balance. The 2.0-liter is also quieter for improved Noise Vibration Harshness (NVH) with additions such as a more rigid crank case with integrated stiffener; a lighter resin cylinder head; and a ribbed oil pan.

The M20A-FKS is equipped with Toyota’s latest D-4S fuel-injection that uses high-pressure direct-injection and low-pressure PFI (Port Fuel Injection). The setup adapts its injection method based on driving conditions to optimize combustion.

The engine also features Dual VVT-i (Variable Valve Timing-intelligence), with VVT-iE (Variable Valve Timing-intelligence by Electric motor) on the intake side and VVT-i on the exhaust. VVT-iE uses one electric motor instead of oil pressure to control the variable valve timing. Together, the valve timing systems enhance power output and fuel economy, and cut harmful emissions.

Other notable improvements to the Dynamic-Force engine include:

- Longer stroke, with compression up to 13:1.
- Enlarged valve nip angle.
- Enhanced intake port efficiency with laser clad valve seat enables a higher rate of combustion, high tumble flow, and high intake air flow volume.
- Pistons with round top surface and slanted side wall support consistent tumble flow and maintain rapid combustion maintained. Further, there is less knocking, supporting the higher compression ratio. Toyota also reduced friction between piston skirt and cylinder.
- Lubrication was enhanced with three oil jets dedicated to each cylinder, supporting better fuel economy, dynamic performance, less knocking, and less oil consumption.
- A lighter weight timing chain contributes to low cabin noise and reduced friction.
- A drain path within crank case returns oil from cylinder head to oil pan. This results in less oil agitation caused by the crankshaft, which means less rotation resistance.
- A connecting rod made of high strength steel with optimized shape reduces weight.
- The concave profile of the camshaft increases valve lift amount.
- An optimized water jacket in head and block enhances cooling and reliability.

- Direct Shift-CVT: A New Type of Continuously Variable Transmission
- New TNGA Dynamic Force 2.0L engine for 2019 Corolla Hatchback smaller, more powerful than 1.8L
- Toyota unveils new TNGA-based engines and transmissions and improved hybrid systems; deployment begins in 2017