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A compact, high-performance and durable metal-supported catalyst has been developed by using the properties of the metal support effectively. The advantages of the metal-surpported catalyst against the ceramic-supported one are higher geometrical surface area, higher heat conductivity and thinner wall thickness. Higher geometlical surface area and higher heat conductivity lead to higher conversion efficiency after durability test and it allows reduction in catalyst volume. And the thinner wall thickness lowers gas flow resistance. But also, the metal-supported catalyst has the disadvantage of larger heat expansion and it requires special structure and material.

Excellent fuel economy and high performance have been urgent in Japanese automobile industries. With increasing engine power, many of the power train components have to withstand higher loads. Differential pinion gear being one of those highly stressed parts, excellent fatigue and shock resistance have been demanded. At first the fundamental study on the fatigue and impact crack behavior of carburized components was studied and the new grade composed of 0.18%C-0.7%Mn-1.0%Cr-0.4%Mo was alloy designed. Furthermore, Si and P is reduced less than 0.15 and 0.015%, respectively aiming at the reduction of intergranular oxidation and improved case toughness. The differential gear assembly test has proved that the new grade shows three times as high impact strength as that of conventional steel, SCM418, and almost the same as that of SNCM420 containing 1.8%Ni.

THIS PAPER presents an advanced heads-up display which has been newly developed for use in 88 Nissan Silvia model. The HUD consists of a projector with a newly developed high brightness VFD and light-selective film used as a combiner which is coated on the windshield. This combination provides good display legibility even under bright sunlight. The display shows the vehicle speed in a three-digit reading at distance of more than one meter from the driver's eyes. The windshield-coated combiner conforms to U.S. safety standards concerning light transmittance, abrasion and other performance requirements. Experimental data are also presented which substantiate the HUD's high legibility and confirm its effect in enhancing the driver's attention toward the road ahead

Maintaining reliability of the connecting rod bearing is a very important subject, and the following is a problem that needs to be overcome. Predicting reliability has generally depended on minimum oil film thickness (M.O.F.T), but recently, the engines of passenger cars which have greater power and speed potential than conventional ones are sometimes run beyond their M.O.F.T. limit (a degree of roughness around the crank shaft's axis.) In such a case, it is so difficult to predict reliability according to M.O.F.T., that we need a new index which directly shows seizure and wear. For this purpose, we found that the crank shaft pin temperature can be a key cause of seizure and wear according to an analysis of the relationship between its temperature and the seizure and wear caused intentionally. Using this method, we confirmed that the combination of bearing and crank shaft materials is very important for preventing seizure and wear.

A new method was developed to help determine the conditions that would create adhesion strength of heat-resisting coatings formed in plasma spraying. This method is a combination of an experiment design that uses a Latin square and multiple regression analysis. Since it allows the direct analysis of experimental data, conditions can be determined in one third of the number of tests required by conventional experimental methods. The multiple regression equation gained through this study is also effective in comparing the heat resistance of the heat-resisting coating.

Japan Automobile Standards Organization (JASO) Engine Oil Sub-committee have been working on the unification of the engine oil evaluation test procedures in Japan. The Engine Oil Sub-committee participated in the recent activity of the worldwide engine oil standardization of SAE and ISO. As one of the chain of activities, JASO tests M328, M331, and M333 (valve train wear, detergency and high temperature oxidation respectively) were conducted on the REOs of ASTM and CEC to find the correlation. The detergency tests (varnish and sludge) showed good correlation with the ASTM REOs. CEC good and poor reference oils seemed to give good results in JASO valve train wear test, while ASTM reference oils unexpectedly gave opposite results in Japanese valve train wear tests.

Engines in Japan have higher output versus small displacement (bhp/liter) and require low phosphorus content in the engine oils to meet the most stringent exhaust emission regulation in the world. The market survey of typical API SF oils in Japan showed that the average phosphorus content was approximately 0.07 %. Under such circumstances engine oils provide good performance with the usage of secondary zinc di-alkyldithiophosphates (Zn DTP) for valve train wear protection, addition of friction modifiers for fuel economy, etc.

Basic vehicle performance, such as Safety, Comfort and Economy, are by dependent on tire performance, and it is the air pressure in the tire which assures this performance. However, tire air has a tendency to leak naturally, making it necessary to check them periodically. Since a deterioration in vehicle performance resulting from a drop on tire air pressure can not be directly felt by the driver, the number of people maintaining their tires sufficiently is relatively few. There have been many tire pressure warning devices developed which advise the driver when the pressure drops below a prescribed level. Differing from conventional devices, the TWD-III features a 7-step digital display (at a pitch of 0.1 kgf/cm2) which shows the pressure of each tire within an optional range, and it also has a flat tire warning function. The employment of echo effect from clystal vibrator resonance precludes the need to attach a power source on the tire.

The exhaust system is often one of the main sources of vehicle noise. A new type of exhaust silencer made of porous sintered aluminum and installed at the end of the exhaust tube considerably reduces this noise, with no rise in back pressure. The mechanism of noise abatement is analyzed utilizing fluid dynamic analysis techniques. It is concluded that noise reduction results mainly from the fluid dynamic effects arising from the gas permeability of the material. Among these effects are the boundary layer control effect of the inner flow, flattening of the velocity profile, heat dispersion effect, decrease in turbulence of flow, smoothing of exhaust pulsation, contraction of the mixing region, and the resulting large decrease in the volume of the noise source. In regard to acoustical effect, the sintered metal can be thought of as Helmholtz resonators. The change in the end condition as an acoustic tube also reduces the peak level of acoustic resonance.

JIS SCM440M (SAE4140H), heat treated to the strength level of 120 to 140 kgf/mm2(171 to 199 ksi) -ISO 12.9 class-, is currently used for cylinder head bolts of Japanese passenger cars. Lower alloy steels, such as SAE 1541 for example, have not been substituted for JIS SCM440H so far because of their high susceptibility to delayed fracture. Daido Steel has tackled this problem and succeeded in applying the lower alloy SAE 1541 steel to 12.9 class cylinder head bolts by enhancing the resistance to delayed fracture by reducing impurities, especially sulphur. In this paper mechanical properties and delayed fracture characteristics of SAE 1541-ULS (Ultra Low Sulphur) steel are reported. 1541-ULS (S<0.005%, S+P< 0.020%) shows outstanding resistance to delayed fracture compared to conventional steel. Furthermore, the amount of MnS inclusions decreases remarkably in ULS steel, which results in high toughness.

Door guard beams have been developed through the utilization of ultra high strength steel (tensile strength>100 kg/mm2). At first, the sheet metal gauge was reduced in proportion to the strength of the ultra high strength without changing the shape of the beam section. This caused beam buckling and did not meet guard beam specifications. Analyzing this phenomena in accordance with the buckling theory of thin plates, a design criteria that makes effective use of the advantages of ultra high strength was developed. As a result, our newly designed small vehicle door guard beams are 20% lighter and 26% thinner than conventional ones. This makes it possible to reduce door thickness while increasing interior volume.

Various heat resistant alloys are being introduced for use in automobile emission equipment, such as thermal reactors and catalytic converters. For the past several years Japan has been developing alloys which emphasize oxidation resistance. Therefore, oxidation phenomena have been thoroughly researched and clarified. On the other hand, embrittlement, which is a marked deterioration similar to oxide deterioration, has not been studied sufficiently. The major subjects of investigation were the two forms of embrittlement in austenitic heat resistant alloys, caused by the precipitation of σ phase and the absorption of Nitrogen. Useful information was obtained from these results.

Fatigue tests on a body in white have been made with torsional load and compared with previous results for assessments, where it was difficult to agree with proving ground tests in evaluating the life. Modifying the above mentioned fault, a programmed fatigue test method on the body in white is presented in this paper. The newly developed programmed fatigue test method is the simultaneous loading of the bouncing and torsional modes to a body in while by an electrohydraulic fatigue testing machine in accordance with the programmed sprung mass accelerations. Applying this method, the comparatively accurate assessment of proving ground test was made at the condition of the body in white, and the development period for body construction was shortened.