This product was developed for the purpose of suppressing pre-ignition (abnormal combustion) that may occur in a turbocharged direct-injected engine. Against the background of the demands of the times to reduce CO2 emissions and improve fuel efficiency, the engine is downsized and designed to obtain the same power as a conventional engine by installing a turbocharger and operating it from the low revolution range. The low revolution range under high load condition is the area where the possibitly of adnormal combustion is feared, and one of the causes is related to the components contained in the engine oil. In consideration of these factors, the blending balance of the functional addictives was designed exclusively for LSPI (low-speed pre-ignition), and the molecular weight distribution of the base oil was optimized to prevent the oil from rising into the combustion chamber.