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The objective of this study was to develop a test method for heavy-duty HEVs using a hardware-in-the-loop simulator (HILS) to enhance the type-approval-test method. To achieve our objective, HILS systems for series and parallel HEVs were actually constructed to verify calculation accuracy. Comparison of calculated and measured data (vehicle speed, motor/generator power, rechargeable energy storage system power/voltage/current/state of charge, and fuel economy) revealed them to be in good agreement. Calculation error for fuel economy was less than 2%.

Assuming friction sparks in a vehicle crash, the ignitability of gasoline, light oil and paper by grinding sparks were studied. The temperature of ground sparks elevates from 1323K to 1373K, and that is about 2.1 times of the flash point of gasoline in Kelvin and about 2.6 times of that of light oil. At the present, however, pieces of paper and fuels to be contained are more ignitable than such liquid fuels as gasoline by grinding hot particles. The heat transfer from a hot particle to air was also studied to determine the influence of the particle size on the ignitability of combustible mixtures. Most of ground particles are considered to be about 0. 1mm to 0. 2mm in size, and particles of larger sizes are not likely to be generated by the friction of a vehicle body against the road surface on crash. Therefore it will be rare for the spilt fuel like gasoline or light oil to be ignited by hot particles far from the friction point on vehicle crash.

Ultra-low energy consumption and ultra-low emission vehicle technologies have been developed by combining petroleum-alternative clean energy with a hybrid electric vehicle (HEV) system. Their component technologies cover a wide range of vehicle types, such as passenger cars, delivery trucks, and city buses, adsorbed natural gas (ANG), compressed natural gas (CNG), and dimethyl ether (DME) as fuels, series (S-HEV) and series/parallel (SP-HEV) for hybrid types, and as energy storage systems (ESSs), flywheel batteries (FWBs), capacitors, and lithium-ion (Li-ion) batteries. Evaluation tests confirmed that the energy consumption of the developed vehicles is 1/2 of that of conventional diesel vehicles, and the exhaust emission levels are comparable to Japan's ultra-low emission vehicle (J-ULEV) level.

In order to investigate the impact of the Ethanol content on existing domestic Gasoline vehicles, we conducted an exhaust gases test, a fuel evaporative emissions test, a high-temperature driveability test, and a material impact test. As a result, no safety problems occurred in the metal material impact test at an Ethanol content of 3% or less. In the exhaust gases test, the fuel evaporative emissions test, and the high-temperature driveability test, no problems occurred at an Ethanol content of 3% or less. Based on these results and discussions conducted by the fuel policy subcommittee of the advisory committee for natural resources and energy survey, it was concluded that the Ethanol content in Gasoline must be 3% or less and the oxygenate (alcohol etc.) content must be limited to a value corresponding to a total oxygen content of 1.3% or less. The results obtained by this study were reflected in the Japanese Gasoline compulsory quality regulations.

Evaporative emissions of Japanese older and current vehicles (1990-1998MY) and U.S. current vehicles, which were adapted to federal regulations in 1996, were investigated using typical Japanese gasoline. Japanese older and current vehicles exhibited high levels of Running Loss (RL), Hot Soak Loss (HSL) and Diurnal Breathing Loss (DBL), and their emissions showed strong Reid vapor pressure (RVP) dependence. On the other hand, U.S. vehicles showed very weak RVP dependence, between 62kPa and 76kPa. Their emissions also showed very low levels of RL, HSL and DBL. These results suggest RVP reduction is just effective for Japanese older and current vehicles. Evaporative emissions of Japanese and U.S. vehicles were also tested according to a new Japanese test procedure and the 35 degrees centigrade RL test procedure. In the case of the RL and DBL tests, the impact of test conditions on evaporative emissions was discussed as well.