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The new Toyota FCV “Mirai” has reduced the weight, size, and cost of the high-pressure hydrogen storage system while improving fueling performance. The four 70 MPa tanks used on the 2008 Toyota FCHV-adv were reduced to two new larger diameter tanks. The laminated structure of the tanks was optimized to reduce weight, and a high-strength low-cost carbon fiber material was newly developed and adopted. The size of the high-pressure valve was reduced by improving its structure and a high-pressure sensor from a conventional vehicle was modified for use in a high-pressure hydrogen atmosphere. These innovations helped to improve the weight of the whole storage system by approximately 15% in comparison with Toyota FCHV-adv, while reducing the number of component parts by half and substantially reducing cost. The time required to fuel the FCV was greatly reduced by chilling the filling gas temperature at the hydrogen filling station to −40°C (as per SAE J2601).

The newly-developed 2JZ engine series is available in two types; a naturally aspirated 2JZ-GE and a turbo charged 2JZ-GTE. Both have in-Line-6 cylinder arrangement and displacement volume of 2.997 liters and have attained many features expected for the engines of new era by utilizing new technologies, such as DOHC 4 valve, high compression ratio, a highly rigid structural design which is realized by extensive use of the CAE, a serpentine accessory drive belt, and auto tensioners for timing belt and accessory belt systems. These engines are stroke up versions of the 1JZ engines. The 2JZ-GE engine, which has been developed for the SC300, delivers high performance of 169 KW/6000rpm and 284 Nm/4800rpm by adopting a variable induction system, a knock-control system with two sensors, etc. The other type, the 2JZ-GTE engine which has been developed for the Aristo in japan includes a TWO-WAY-TWIN-TURBO’ system equipped with ceramic turbine wheels.

A new hybrid transmission has been developed for all-wheel-drive (AWD) cars, and is used in the new Lexus LS600h and LS600hL for its first application. It has a compact layout consisting of a power-split device, generator, high-output electric motor, and a two-stage speed reduction device. Combined with a 5-liter V-8 engine, it achieves power performance rivaling 6-liter engine vehicles, the fuel efficiency of a medium-class vehicle, and outstanding quietness. This paper describes the structure, performance, and shift control technology of this hybrid transmission.

Efficiency of Driveshafts have not been analyzed in great detail in the past due to their relatively high efficiency. However, it is possible to obtain about a 0.1 percent increase in fuel economy by decreasing driveshaft torque losses by about 20 percent, owing to the combination mode fuel calculation. In order to improve fuel economy it is necessary to increase the efficiency of the constant velocity universal joint (C.V.J.) used for driveshafts. Additionally, propeller shafts with improved heat characteristics are required. It is for these reasons that this project is conducted. In this paper, the motion of two typical joint used for front-engine, front-drive passenger cars is analyzed geometrically and efficiency formulas are derived. One of the joints is a Rzeppa joint, used on the wheel side of the driveshaft and the other is a tripot joint, used on the differential side. These formulas are then verified by experiment.

For the launch of the redesigned Lexus LS, a new 3.5 L V6 twin turbo engine has been developed aiming at unparalleled performance on four axes, “driving pleasure”, “power-performance”, “quietness” and “fuel economy”. To achieve outstanding power-performance and high thermal efficiency, the specifications have been optimized for high speed combustion. The maximum torque of 600 Nm, power of 310 kW (yielding specific power of 90 kW/L), and the maximum thermal efficiency of 37% have been achieved using several new technologies including a high efficiency turbocharger. A prototype vehicle equipped with this engine and Direct-Shift 10AT achieved a 0-60 mph acceleration time of 4.6 sec, with extremely good CAFE combined fuel economy of 23 mpg and power-performance aligned with V8 turbocharged offerings from competing OEM’s.