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For reduction of fuel consumption, a new device “Water Jacket Spacer” which improves temperature distribution of a cylinder block bore wall was developed. In the case of a conventional cylinder block, coolant flow concentrates at the bottom and middle region of the water jacket. While temperature of the upper bore wall is high (due to high-temperature combustion gas) the temperature of the lower bore wall is low, since its only function is to support the piston. When the developed spacer is inserted into a water jacket, the coolant flow concentrates at the upper part of the jacket. As a result, cooling ability to the upper bore wall was improved and temperature of lower bore wall was increased, thereby reducing fuel consumption.

This paper proposes a technology to reduce vehicle surge during towing that utilizes motors and shifting to help ensure comfort in a parallel HEV pickup truck. Hybridization is one way to reduce fuel consumption and help realize carbon neutrality. Parallel HEVs have advantages in the towing, hauling, and high-load operations often carried out by pickup trucks, compared to other HEV systems. Since the engine, motor, torque converter, and transmission are connected in series in a parallel HEV, vehicle surge may occur when the lockup clutch is engaged to enhance fuel efficiency, similar to conventional powertrains. Vehicle surge is a low-frequency vibration phenomenon. In general, the source is torque fluctuation caused by the engine and tires, with amplification provided by first-order torsional driveline resonance, power plant resonance, suspension resonance, and cabin resonance. This vibration is amplified more during towing.

From the viewpoint of primary energy diversification and CO2 reduction, interests of using Biomass Fuel are rising. Some kinds of FAME (Fatty Acid Methyl Ester), which are obtained from oil fats like vegetable oil using transesterification reaction with methanol, are getting Palm Oilpular for bio-diesel recently. In this study, we have conducted many experiments of palm oil hydrogenations using our pilot plants, and checked the reactivity and the pattern of product yields. As a result, we figured out that the hydrocarbon oil equivalent to the conventional diesel fuel can be obtained from vegetable oils in good yield under mild hydrogenation conditions. Moreover, as a result of various evaluations for the hydrogenated palm oil (oxidation stability, lowtemperature flow property, LCA, etc.), we found that the hydrogenated palm oil by our technology has performances almost equivalent to conventional diesel fuel.

Exhaust gas recirculation (EGR) can be used to mitigate knock in SI engines. However, experiments have shown that the effectiveness of various EGR constituents to suppress knock varies with fuel type and compression ratio (CR). To understand some of the underlying mechanisms by which fuel composition, octane sensitivity (S), and CR affect the knock-mitigation effectiveness of EGR constituents, the current paper presents results from a chemical-kinetics modeling study. The numerical study was conducted with CHEMKIN, imposing experimentally acquired pressure traces on a closed reactor model. Simulated conditions include combinations of three RON-98 (Research Octane Number) fuels with two octane sensitivities and distinctive compositions, three EGR diluents, and two CRs (12:1 and 10:1). The experimental results point to the important role of thermal stratification in the end-gas to smooth peak heat-release rate (HRR) and prevent acoustic noise.

In recent years, the automotive manufacturers have been working to reduce fuel consumption in order to cut down on CO2 emissions, promoting weight reduction as one of the fuel saving countermeasures. On the other hand, this trend of weight reduction is well known to reduce vehicle stability in response to disturbances. Thus, automotive aerodynamic development is required not only to reduce aerodynamic drag, which contributes directly to lower fuel consumption, but also to develop technology for controlling unstable vehicle behavior caused by natural wind. In order to control the unstable vehicle motion changed by external contour modification, it is necessary to understand unsteady aerodynamic forces that fluctuating natural wind in real-world environments exerts on vehicles. In the past, some studies have reported the characteristics of unsteady aerodynamic forces induced by natural winds, comparing to steady aerodynamic forces obtained from conventional wind tunnel tests.

In order to clarify future automobile technologies and fuel qualities to improve air quality, second phase of Japan Clean Air Program (JCAPII) had been conducted from 2002 to 2007. Predicting improvement in air quality that might be attained by introducing new emission control technologies and determining fuel qualities required for the technologies is one of the main issues of this program. Unregulated material WG of JCAPII had studied unregulated emissions from gasoline and diesel engines. Eight gaseous hydrocarbons (HC), four Aldehydes and three polycyclic aromatic hydrocarbons (PAHs) were evaluated as unregulated emissions. Specifically, emissions of the following components were measured: 1,3-Butadiene, Benzene, Toluene, Xylene, Ethylbenzene, 1,3,5-Trimethyl-benzene, n-Hexane, Styrene as gaseous HCs, Formaldehyde, Acetaldehyde, Acrolein, Benzaldehyde as Aldehydes, and Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(k)fluoranthene as PAHs.

High fuel efficiency and low emission technologies, such as Direct Injection (DI) gasoline and diesel engines and hybrid powertrains, have been developed to resolve environmental and energy resource issues. The hybrid powertrain system has achieved superior power performance as well as higher system efficiency and is expected to be a core powertrain technology because it is compatible with various power sources including fuel cells. It becomes important to control complicated hybrid systems that consist of not only a powertrain but also vehicle systems such as regenerative braking. Model-based control and calibration enables both control strategy optimization and control system development efficiency improvement.

Toyota developed a new hybrid unit “L4A0” for the new Tundra, which creates both good drivability and environmental performance. To ensure off-road, towing performance and typical truck driving characteristics, the unit is based on a transmission with a torque converter and a multi-plate lock up clutch, with a motor-generator and K0 clutch installed between the engine and transmission. The motor-generator and K0 clutch are built into a module, making it possible to create new hybrid units by combining the module with various transmissions. The unit features many different motor controls. For example, in the case of step-in acceleration input, in order to achieve the desired output torque, typically a kick-down shift is necessary [1]; however, by utilizing “L4A0” both high response and high power output is achieved even without a kick-down shift. This is accomplished by assisting the engine with the motor-generator even when the engine torque is delayed at low engine speeds.

The renewed platform of the upcoming flagship front-engine, rear-wheel drive (FR) vehicles demands high levels of driving performance, fuel efficiency and noise-vibration performance. The newly developed driveline system must balance these conflicting performance attributes by adopting new technologies. This article focuses on several technologies that were needed in order to meet the demand for noise-vibration performance and fuel efficiency. For noise-vibration performance, this article will focus on propeller shaft low frequency noise (booming noise). This noise level is determined by the propeller shaft’s excitation force and the sensitivity of differential mounting system. In regards to the propeller shaft’s excitation force, the contribution of the axial excitation force was clarified. This excitation force was decreased by adopting a double offset joint (DOJ) as the propeller shaft’s second joint and low stiffness rubber couplings as the first and third joints.

TOYOTA has developed the world's first eight-speed automatic transmission (AA80E) for front-engine, rear-drive passenger cars. The AA80E developed for high-torque engines raises the level of power performance and fuel efficiency. To meet the size requirements needed for mounting in a passenger car application, an 8-speed geartrain, torque converter, transmission case and hydraulic control device were all newly-developed. Furthermore, the AA80E has benefited from technical developments to achieve an extremely high level of quietness and shifting performance. In this paper, the details of the AA80E are introduced.

Toyota Motor Corporation has developed a new six-speed automatic transmission AB60E for longitudinal front engine rear wheel drive (RWD) vehicles. This transmission development was aimed at an improvement of power performance and fuel economy, while achieving a lightweight, compact package and a high torque capacity. In order to achieve this target, a high-capacity ultra-flat torque converter, a highly-rigid transmission case, and an ATF warmer with a valve to switch ATF circuits to an air-cooled ATF cooler have been newly developed. Moreover, a new transmission mode control logic “TOW / HAUL” has been developed to improve power performance and driveability during trailer towing. This automatic transmission has adopted the same gear train and hydraulic control system as the conventional six-speed automatic transmission A760E. This paper describes the structure, major features and performance of the transmission in detail.

Toyota Motor Corporation has recently developed a new six-speed automatic transmission (A761E) for Front Engine Rear Wheel Drive (FR) vehicles. Following the general trend of increased shift stages and a wider range of gear ratios, this six-speed automatic transmission has been developed with attention paid to the gear steps and a wider range of gear ratios. By balanced selection of close-ratio gears in a wider range, the change greatly improves the power performance and fuel economy of the vehicle. To further improve fuel economy we have adopted new technologies such as low-viscosity ATF, neutral control, and deceleration control by extending the fuel cut range (reset speed). We have also adopted a flat-shaped torque converter, small solenoids, an aluminum oil pump cover, etc. to realize the lightest six-speed automatic transmission in the world.

Toyota Motor Corporation has developed a new five-speed automatic transmission (A750E/A750F) for longitudinal front engine rear wheel drive (RWD) vehicles. The development of this transmission has been aimed at improving fuel economy and power performance, achieving the world's top-level weight and compactness, while maintaining high torque capacity. In order to achieve this purpose, the gear train, torque converter, and other components are completely changed, and advanced technology has been applied. Moreover, this automatic transmission has achieved high-quality shift feel and quiet performance. This paper describes the major features and performance of this transmission in detail.

AISIN AW has developed a new Continuously Variable Transmission (hereafter CVT) with torque converter for small capacity engines. The target vehicles are B class cars. The following items are the concept of the development. - Compact size to be applicable to small cars in Japan (K-car). - The lightest in the world. - Low noise level in addition to improved fuel consumption. The CVT introduces neutral-control logic and a long-travel damper on the torque converter for expansion of the lock-up area.

New engine controls have been developed for the turbocharged Lexus NX200t to improve driving power by reducing engine torque output lag. Drive power management functions have been centralized in an integrated drive power control system. The newly developed controls minimize the potential reduction in drivability associated with the adoption of a turbocharged engine while improving fuel efficiency. General driveability issues commonly associated with a turbocharged engine include sudden increases in drive power due to the response lag of the turbocharger, and higher shifting frequencies if this response lag triggers a disturbed accelerator operation pattern by the driver. The developed technologies detect and control sudden increases in drive power to create the optimum drive power map, and reduce unnecessary shifts even if the driver's accelerator operation is disturbed.

Newly developed 2VZ-FE engine for CAMRY is a 2.5-liter water cooled and V-type 6-cylinder engine exported from TOYOTA for the first time. This engine has the TOYOTA original 4-valve DOHC system. That is, exhaust camshafts driven by intake camshafts using scissors gears. By its compact configuration with the gear driven camshafts, this V-type 6-cylinder engine is mounted on a front-wheel-drive vehicle which originally had an in-line 4-cylinder engine. By increasing IVZ-FE engine displacement (for domestic), compact pentroof-type combustion chambers, optimum air-fuel ratio and ignition timing by TCCS (TOYOTA Computer Controlled System) and other technologies, a high performance 153HP/5600rpm and a large torque 155ft·lbs/4400rpm have been achieved with a low fuel consumption.

The new eight-speed automatic transmission direct shift-8AT (UA80) is the first automatic transmission to be developed based on the Toyota New Global Architecture (TNGA) design philosophy. Commonizing or optimizing the main components of the UA80 enables compatibility with a wide torque range, including both inline 4-cylinder and V6 engines, while shortening development terms and minimizing investment. Additionally, it has superior packaging performance by optimizing the transmission size and arrangement achieving a low gravity center. It contributes to Vehicle’s attractiveness by improving driving performance and NVH. At the same time, it drastically improves fuel economy and quietness.

This paper presents CAE method enhancement which realizes time domain gear noise simulation to practical use for AISIN AW automatic transmission assembly model. Today, vehicle electrification has been accelerating due to severe fuel consumption regulations. Furthermore, as quietness of interior noise of vehicle is improving, further gear noise reduction of A/T is imperative. Currently, as one of the countermeasures for realizing lightweight and NV reduction, we apply elongate holes in gear flange. Although the effect of gear noise reduction is confirmed in evaluations, the mechanism for this gear noise reduction by the elongate holes has not been clarified completely and the current simulation based on modal analysis with static condition cannot replicate actual NV phenomena of A/T assy. Furthermore, it takes an enormous amount of time and cost since the design study for elongate holes is based on the evaluation results.

This paper presents the thermal management of a hybrid vehicle (HV) using a heat pump system in cold weather. One advantage of an HV is the high efficiency of the vehicle system provided by the coupling and optimal control of an electric motor and an engine. However, in a conventional HV, fuel economy degradation is observed in cold weather because delivering heat to the passenger cabin using the engine results in a reduced efficiency of the vehicle system. In this study, a heat pump, combined with an engine, was used for thermal management to decrease fuel economy degradation. The heat pump is equipped with an electrically driven compressor that pumps ambient heat into a water-cooled condenser. The heat generated by the engine and the heat pump is delivered to the engine and the passenger cabin because the engine needs to warm up quickly to reduce emissions and the cabin needs heat to provide thermal comfort.

In order to reduce CO₂, Electric Vehicles (EV) and Hybrid Vehicles (HV) are effective. Those types of vehicles have powertrains from conventional vehicles. Those new powertrains drastically improve their efficiency from conventional vehicles keeping the same or superior power performance. On the other hand, those vehicles have an issue for thermal energy shortage during warming up process. The thermal energy is very large, and seriously affects the fuel economy for HV and the mileage for EV. In this paper, we propose VHDL-AMS multi-domain simulation technique for the estimation of the vehicle performance at the concept planning stage. The VHDL-AMS is IEEE and IEC standardized language, which supports not only multi-domain (physics) but also encryption. The common modeling language and encryption standard is indispensable for full-vehicle simulation.