API Service Category SG was first introduced in 1989 for use in gasoline engines and is not suitable for use in engines introduced after 1993.
API has discontinued licensing engine oils against API SG and it is considered to be an obsolete specification.
Engine lubricants claiming to meet API SG are still marketed in some regions around the world. These oils are typically formulated to be SAE 15W-40 or heavier and are unlikely to be suitable for use in the majority of engines. Refer to engine manufacturer recommendations to determine if API SG oils are suitable for use in a specific application.
For more information on API SG, contact your Lubrizol representative.