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Engine performance has been investigated of currently gasoline powered passenger car engines converted to methanol and gasoline mixtures. A 4 cycle, 4 cylinder, 1.6 liter displacement engine for a conventional passenger car was tested varying the fueling condition. The mixing ratio of methanol to gasoline was changed from zero percent to one hundred percent, discreetly. Evaluation of engine performance was made to find the optimum air-fuel ratio and spark timing in each mixed fuel condition. It has been clarified that the stoichiometric air-fuel ratio in the mixed fuel can be determined by the mixing ratio P, as an expression of The MBT(minimum spark advance for the best torque) characteristics for each mixed fuel codition show that the large retardation of spark timing will be required for the higher mixture ratio fuels. Changes in characteristics of fuel supply and air-fuel ratio sensing devices were investigated experimentally.

To detect an air-fuel ratio in wide range is very important to control the automotive engines with low fuel consumption and low exhaust emissions. Although the application of zirconia electrolyte for this purpose has been proposed by the authors several years ago, there remained several problems due to the contamination of gas diffusion apertures which are exposed to the exhaust gas environment. Here the behavior of ions transported in zirconia electrolyte have been analyzed to optimize the structure and characteristics, and to guarantee the long life operation of sensor. Gas contents and their reactions in combustion process under the wide range air-fuel ratio have been analyzed, and these results were reflected to the analysis of ion transportation in zirconia electrolyte. Experimental results supported the analytical results, and they showed the possibilities of long life operation of zirconia air-fuel ratio sensor utilizing ion transportation phenomena.

A multiplexed transmission system utilizing newly developed optical polymer has been proposed. The system is composed of a star-shaped optical network, in which optical signals can be transmitted bi-directionally through a fiber and optical branches between the central and local controllers. The new polymer optical fiber has been developed and adopted for this system, and it was designed to be durable to the high temperature in automotive engine rooms. The high temperature resistibility of the fiber has been achieved with utilization of a thermo-setting resin for the core materials. The optical loss characteristics of the fiber is as low as 0.50 dB/m at 660 nm wavelength.