What does Castrol A3B4 mean?

[DeLeo]

Castrol is a brand of engine oil, and A3B4 is the model number. 'A' represents gasoline engine oil, with types such as A1, A3, A5, etc., while 'B' represents light-duty diesel engine oil, with types like B1, B3, B4, B5, etc. The higher the number, the higher the grade. A3B4 is a dual-purpose oil for both gasoline engines and light-duty diesel engines, with a relatively high grade. Relevant information about engine oil is as follows: 1. Introduction: Engine oil, also known as engine lubricant (English name: Engine-oil), has a density of approximately 0.91×10³ (kg/m³). It lubricates and reduces friction in the engine, assists in cooling, seals against leaks, prevents rust and corrosion, and provides shock absorption. It is often referred to as the 'blood' of a car. 2. Composition: Engine oil consists of base oil and additives. The base oil is the main component of lubricating oil, determining its basic properties. Additives compensate for and improve the shortcomings of the base oil, imparting new properties, and are an important part of lubricating oil.