Japanese industrial research on lean combustion: A case study: International Research Monitoring Program

Abstract

In recent years, Japanese automakers have introduced a number of successful lean-combustion engines. These engines, in addition to the general expertise in building small cars, have made the Japanese automobiles into the gas mileage champions of the US market. The lean-combustion engines also provide very satisfactory performance and acceptable emissions. United States automakers and research managers, who were probably better informed about lean-combustion than the Japanese were, actively investigated lean-combustion but did not develop an engine. This report examines the basis for the Japanese innovations, the research that took the Japanese past the US state of the art to permit engine development. A preliminary review of recent (1980s) Japanese literature did not turn up strong evidence of new research activity in the lean-combustion area, but did provide background on new engines developed by several major manufacturers. The study was conducted solely through the Japanese and US published literature, with emphasis on early research conducted in the 1970s. This report presents an example of how Japanese research progress can be examined by reviewing the Japanese research literature. Although useful information was obtained by this method, it is still difficult to get a complete picture. When reviewing the literature, as was done for this report, one must remember that the marginal use of references by Japanese researchers obscures prior work, as does the tendency of the Japanese to publish several articles on similar or identical topics. 50 refs., 15 figs.