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A metal support for use in an automotive catalyst is exposed to the severe heat cycle brought about by the intermittent flow of a high temperature exhaust gas. Accordingly, the metal support must have high beat resistance(ex. oxidation resistance) and a rigid structure. Therefore, 20% chromium-5% aluminum ferritic stainless steel(containing small quantities of rare earth metals and titanium) is used as a highly beat resistant honeycomb foil in addition to a highly mechanical durable brazing honeycomb structure. This study examined the durability of a metal honeycomb installed in a gasoline engine. Both an engine bench durability test of a manifold converter type metal support which is connected directly to the exhaust manifold of the gasoline engine and a vehicle durability test of an under the floor type metal support were carried out to evaluate oxidation damage of the metal honeycomb as well as its mechanical durability.

In order to meet requirements for lower fuel consumption, we have developed a technique for significantly decreasing valve train friction for a direct acting OHC engine. Droplets of pure titanium generated by the titanium nitride coating process of the shims improves the surface roughness of the cams, which eliminates the need to polish the cams. In an engine with these shims, the surface roughness of the cams is considerably improved within a few minutes of initial operation by the polishing action of the droplets. Valve train friction is greatly reduced by improving the surface roughness of the cams and shims, which results in better fuel economy.

In October 1998, a new mass-produced car with titanium engine-valves was released from TOYOTA Motor Corporation. Both intake and exhaust valves were manufactured via a newly developed cost-effective P/M forging process. Furthermore, the material which was specially designed for the exhaust one is a unique titanium metal matrix composite (MMC). This paper discusses the materials and manufacturing methods used. The tensile, fatigue strength and creep resistance of the MMC are always superior to those for the typical heat-resistant steel of 21-4N. Both valves have achieved sufficient durability and reliability with a manufacturing cost acceptable for mass-produced automobile parts.

The new Toyota FCV “Mirai” has reduced the weight, size, and cost of the high-pressure hydrogen storage system while improving fueling performance. The four 70 MPa tanks used on the 2008 Toyota FCHV-adv were reduced to two new larger diameter tanks. The laminated structure of the tanks was optimized to reduce weight, and a high-strength low-cost carbon fiber material was newly developed and adopted. The size of the high-pressure valve was reduced by improving its structure and a high-pressure sensor from a conventional vehicle was modified for use in a high-pressure hydrogen atmosphere. These innovations helped to improve the weight of the whole storage system by approximately 15% in comparison with Toyota FCHV-adv, while reducing the number of component parts by half and substantially reducing cost. The time required to fuel the FCV was greatly reduced by chilling the filling gas temperature at the hydrogen filling station to −40°C (as per SAE J2601).