Present Status of Japanese Motor Oils and Extension of Oil Drain Intervals

This paper describes the recent trends in motor oils in Japan and the movement of drain interval extension. The present target proposed by Japanese car manufacturers is mostly the extension from 5,000 km to 10,000 km, that does not look “long drain” and seems to be easily met by conventional SE oils. Recently low ash-low phosphorus oils have been predominating in the market for the purpose of getting longer catalyst durability. Therefore it is our primary concern how to satisfy simultaneously the drain interval extension and low ash-low phosphorus requirements. Valve train wear is still an important item. While some conventional SE oils are deficient in wear protection, a couple of low ash-low phosphorus oils have excellent antiwear performance.