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The wear mechanisms of the methanol engine were studied using dynamometer tests. Formic acid from methanol combustion mixes with the lubricant oil and attacks the metal surfaces. The iso tacho prorissis method was successfully applied to analyze the formic acid content of the used oil. A large amount of condensed water is also formed by methanol combustion and accelerates the wear. Wear can be effectively reduced by shortening lubricant oil change intervals, by using a special oil and by durable surface treatment of engine parts.

Finite element aodels have been developed to analyze drive line and suspension vibration. For the analysis of booming noise, we have addressed the optimization of the differential gear carrier mounting system by using a virtual system and realization of it considering many constraints. To reduce the differential whine noise, a simulation method considering the transmitting error of the differential gear was applied. And we have approached for the subtle arrangements of many structural resonances with detail research of the drive line and suspension. For the reduction of road noise, we adopted the approach of shifting the node of the rear suspension member mode.

The SEA model of wind noise requires the quantification of both the acoustic as well as the turbulent flow contributions to the exterior pressure. The acoustic pressure is difficult to measure because it is usually much lower in amplitude than the turbulent pressure. However, the coupling of the acoustic pressure to the surface vibration is usually much stronger than the turbulent pressure, especially in the acoustic coincidence frequency range. The coupling is determined by the spatial matching between the pressure and the vibration which can be described by the wavenumber spectra. This paper uses measured vibration modes of a vehicle window to determine the coupling to both acoustic and turbulent pressure fields and compares these to the results from an SEA model. The interior acoustic intensity radiating from the window during road tests is also used to validate the results.

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 four-speed automatic transaxle U140E named “Super ECT”. The U140E has achieved compactness which enables it to mount on many new platforms, achieved high efficiency, which contributes to improve fuel economy, and it achieved good shift feeling, response, and reduce noise. This paper shows the major features and performance of the U140E.

The third generation four valve lean combustion engine controlled by newly designed combustion pressure sensor has been developed. This combustion sensor composed of a metal diaphragm and a thin silicone layer formed on devitron piece detects the combustion pressure in the No.1 cylinder. Comparing with the lean mixture sensor equipped in the first and second generation lean combustion engine, the lean misfire limit was detected directly with this sensor, and the lean operation range was expanded, which realized lower fuel consumption and NOx emission. The output torque fluctuation was minimized by precisely compensating the fuel supplied to individual cylinder based on the crank angle sensor signal. Separated dual intake ports, one with the swirl control valve and the other with helical port shape was designed and a twin spray injection nozzle was equipped between those ports. The swirl ratio was lowered from 2.2 to 1.7.

Lean mixture operation and high transient response has been accomplished by the introduction of newly designed Central Injection (Ci) system. This paper describes the effects of Ci design variables on its performance. Lean mixture operation has been attained by optimizing the injection interval, injection timing and fuel spray angle in order to improve the cylinder to cylinder air-fuel ratio distribution. Both air-fuel distribution and transient engine response are affected by the fuel spray angle. Widening the fuel spray angle improves the air-fuel distribution but worsen the transient engine response. This inconsistency has been solved by off-setting the injector away from the center axis of the throttle body and optimizing the fuel spray angle.

The automobile industry currently faces many challenges which may greatly impact on its foundry operations. One of these challenges, consumers'' demand for greater fuel efficiency, can be met by reducing the weight of castings used in automobiles, and minimizing engineering tolerances. In answer to this particular demand, engine foundries have begun to either produce cylinder blocks or other castings with aluminum rather than cast iron. However, if a reduction in weight (thin wall and near-net shaping) can be realized with cast iron, there would be numerous merits from the perspective of cost and compactness and there would be much more flexibility in automotive parts design.

We have developed a method by which the oil flow rate can be measured by using a hot-wire sensor that could be installed in the passages of actual engine lubricant oil. This measuring method proves to have a ±5% accuracy and a 40kHz response that enables ‘real time’ function. Thus, observation of (1) the effect of bearing clearance, and (2) the fluctuating mechanism of the oil flow per 1 degree crank angle from the point of engine start-up to 6000r/min and full load can be achieved, and the timing and quantity of intermittent oil-jet from the oil hole in connecting rod were ascertained.

Toyota Motor Corporation is developing a series of engines belonging to its ESTEC (Economy with Superior Thermal Efficient Combustion) development concept. This paper describes the development of 8NR-FTS after the subsequent launch of the 2.0-liter DI Turbocharged 8AR-FTS. 8NR-FTS is a 1.2-liter inline 4-cylinder spark ignition downsized turbocharged direct injection (DI) gasoline engine. By following the same basic concepts as 8AR-FTS engine [1], the 8NR-FTS incorporates various fuel efficient technologies such as a cylinder head with an integrated exhaust manifold, the Atkinson cycle using the center-spooled variable valve timing with mid-position lock system (VVT-iW), and intensified in-cylinder turbulence to achieve high-speed combustion.

This paper describes a new 2.4-liter 16-valve in-line four-cylinder engine, 2TZ-FE, which has been mounted horizontally on a new minivan, the TOYOTA PREVIA. This engine has the TOYOTA original compact 4-valve DOHC system (scissors gear mechanism), and TOYOTA's newest technologies, such as 75 deg. slant cylinder and Separated accessory Drive System. The compact configuration reduces the height of this engine to only 44Omm (17.3-inches). Engine location is under the flat floor on the midship rear-wheel-drive vehicle and allows the PREVIA to have a spacious cabin with walkthrough. Its high performance, 103kW at 500Orpm and 209Nm at 4000rpm, has been achieved through updated technologies, such as: Knock Controll System (KCS), well studied intake system and exhaust manifold which is made of stainless steel double pipe. At the same time, high reliability and quietness have been achieved for the 2TZ-FE by TOYOTA's updated technologies.

Turbocharged (TC) engines have been introduced these days to improve the fuel economy. It is considered that one possible issue of the TC engine is a pre-ignition at high engine speed because of high temperature and high pressure in the combustion chamber. This study shows the effect of fuel compounds on pre-ignition at 4400rpm. The experimental engine is a naturally-aspirated (NA) engine which is customized to imitate the cylinder temperature and pressure of TC engines. It is known that research octane number (RON) describes anti-knock quality well. Meanwhile the results show that pre-ignition characteristic at high engine speed is dominated by motor octane number (MON) and auto-ignition temperature (AIT) rather than RON.

It is well understood that using lower viscosity engine oils can greatly improve fuel economy [1, 2, 3, 4]. However, it has been impossible to evaluate ultra-low viscosity engine oils (SAE 0W-12 and below) utilizing existing fuel economy test methods. As such, there is no specification for ultra-low viscosity gasoline engine oils [5]. We therefore developed firing and motored fuel economy test methods for ultra-low viscosity oils using engines from Japanese automakers [6, 7, 8]. This was done under the auspices of the JASO Next Generation Engine Oil Task Force (“TF” below), which consists mainly of Japanese automakers and entities working in the petroleum industry. Moreover, the TF used these test methods to develop the JASO GLV-1 specification for next-generation ultra-low viscosity automotive gasoline engine oils such as SAE 0W-8 and 0W-12. In developing the JASO GLV-1 specification, Japanese fuel economy tests and the ILSAC engine tests for evaluating engine reliability were used.

Eliminating brake squeal generated during brake application is an important task for the improvement of comfort in the vehicle. There has been a lot of research made on the problem of brake squeal in the past. And most of the papers presented elaborate on low frequency brake squeal (2-3kHz). However, brake squeal has often the high-frequency vibration. For this reason, we have made research into the high-frequency brake squeal (5-10kHz). Double-Pulsed Laser Holography is a useful method for visualizing small vibration of brake components during brake squeal generation. The results obtained using Holographic Interferometry show the rotaing disc vibrates in the bending mode with diametral nodes. Consequently, we think that the modification of brake disc can eliminate brake squeal, which is caused by self-excited vibration. Then we have calculated natural frequency and its vibration mode of a circular-plate added mass.

It is very important for the vehicle comfort quality to eliminate brake noise. The brake noise can be defined into two phenomena: One is the high-frequency brake squeal (frequency 1-15kHz), we have presented in 1989 SAE Congress(890864) * (2),and the another is the low-frequency brake groan (frequency 200-500Hz). In this paper,the brake groan has been discussed by constituting the theoretical model,in order to clarify the cause of disc brake groan noise. According to the previous study(3), the groan noise has been occurred by the increase of the disc temperature which has influenced on the disc width and the disc material. On the other hand, the groan noise can be observed in the condition of atmosphere temperature indeed. So that the precise phenomenon and cause should be defined. After observing the groan noise on the test bench, we have constructed the theoretical model and taken the numerical method.

In Biodiesel Fuel Research Working Group(WG) of Japan Auto-Oil Program(JATOP), some impacts of high biodiesel blends have been investigated from the viewpoints of fuel properties, stability, emissions, exhaust aftertreatment systems, cold driveability, mixing in engine oils, durability/reliability and so on. This report is designed to determine how high biodiesel blends affect oil quality through testing on 2005 regulations engines with DPFs. When blends of 10-20% rapeseed methyl ester (RME) with diesel fuel are employed with 10W-30 engine oil, the oil change interval is reduced to about a half due to a drop in oil pressure. The oil pressure drop occurs because of the reduced kinematic viscosity of engine oil, which resulting from dilution of poorly evaporated RME with engine oil and its accumulation, however, leading to increased wear of piston top rings and cylinder liners.

For diesel engines, the delay of injection timing causes the white smoke due to unburned fuel in cold conditions. To define the effective engineering against the white smoke, we studied this occurrence mechanism by observing the white smoke in the cylinder through the glass window, and quantitatively measuring some factors. As a result, it is found that the white smoke quantity is closely correlated with the wall adhesion quantity of injected fuel, and proved that the evaporation acceleration by restraint of the fuel adhesion to the combustion chamber wall is effective to reduce the white smoke.

The oil consumption phenomena during transient engine operating condition is analyzed. The investigation of the oil consumption by means of the real-time oil consumption meter shows that higher intake manifold vacuum during engine-brake condition causes a larger amount of transient oil consumption. The reverse blowby gas flow into the combustion chamber from the crankcase is generated by the high vacuum under engine-brake condition. It is found that this reverse gas flow carries the oil into the chamber from the third land of the piston through the ring end gap of the compression rings. The oil on the piston skirt leaks into the third land through the clearance between the oil ring and the cylinder bore. The weakened bore-to-ring contact pressure by the piston slap motion increases the amount of the leakage oil. New ring sets and pistons are developed based on the results of this study.

The reduction of particulate emissions is one of the most important challenges facing the development of future gasoline engines. Several studies have demonstrated the impact of fuel chemical composition on the emissions of particulate matter, more particularly, the detrimental effect of high boiling point components such as heavy aromatics. Fuel contamination is likely to become a critical issue as new regulations such as Real Driving Emissions RDE involves the use of market fuel. The objective of this study is to investigate several experimental approaches to detect the presence of Diesel contamination in Gasoline which is likely to alter pollutant emissions. To achieve this, a fuel matrix composed of 12 fuels was built presenting diesel fuel in varying concentrations from 0.1 to 2% v/v. The fuel matrix was characterized using several original techniques developed in this study.

Improving the engine efficiency to respond to climate change and energy security issues is strongly required. In order to improve the engine efficiency, lower fuel consumption, and enhance engine performance, OEMs have been developing high compression ratio engines and downsized turbocharged engines. However, higher compression ratio and turbocharging cause cylinder pressure to increase, which in turn increases the demand voltage for ignition. To reduce the demand voltage, a new ignition system is developed that uses a high voltage Zener diode to maintain a constant output voltage. Maintaining a constant voltage higher than the static breakdown voltage helps limit the amount of overshoot produced during the spark event. This allows discharge to occur at a lower demand voltage than with conventional spark ignition systems. The results show that the maximum reduction in demand voltage is 3.5 kV when the engine is operated at 2800 rpm and 2.6 MPa break mean effective pressure.