What is the difference between Shell S2 and S3?

[LouisLee]

The differences between Shell S2 and S3 are as follows: Different grades: S2 is currently the highest grade of engine oil; S3 is the second grade. Base oil is the main component of lubricating oil, determining the basic properties of the lubricating oil, while additives can compensate for and improve the shortcomings of the base oil's performance, giving it some new properties. Different oil films: S2 has a relatively strong oil film; S3 has a relatively weak oil film. Engine oil can lubricate and reduce wear, assist in cooling and temperature reduction, seal against leaks, prevent rust and corrosion, and provide shock absorption for the engine. Different protective performances: S2 has relatively strong protective performance; S3 has average protective performance. Gasoline is a volatile, flammable hydrocarbon mixture liquid obtained from petroleum through distillation or cracking, mainly used as fuel for spark-ignited internal combustion engines.