It stipulates the lubricating oil requirements for 2-stroke gasoline engines, such as those used in motorcycles, general-purpose machines, and outboard motors, and was established in 1994. For 2-stroke oil, lubricity, cleanliness, exhaust smoke, and exhaust system blockage are evaluated using the test methods specified in JASO M 340, M 341, M 342, and M 343, resulting in the grades FB, FC, and FD. FA has been abolished. The performance classifications are as follows: • FA: Minimum performance for a 2-stroke engine. • FB: Superior lubricity and cleanliness compared to FA. • FC: Low smoke with excellent performance in reducing exhaust smoke and system blockage compared to FB. • FD: Enhanced cleaning performance at high engine temperatures compared to FC. Additionally, FB, FC, and FD are adopted as EGB, EGC, and EGD, respectively, in
ISO standards. ==See also==