Can different brands of engine oil be mixed together?

[Lawrence]

Different brands of engine oil should not be mixed together. Here are some additional details: 1. The additives in engine oils from different manufacturers vary, and the chemical compositions of these additives differ between brands. 2. Even within the same brand, different product lines can have significant chemical differences. Mixing any two brands of engine oil under the high temperatures in an engine may lead to chemical reactions. There is always a risk that mixing certain oils could cause adverse reactions, such as the formation of flocculents or increased viscosity. 3. Engine oil has a relatively low specific heat capacity and does not inherently have a cooling effect inside the engine. However, during engine operation, the heat generated by fuel combustion is carried back to the oil pan by the oil and then dissipated into the air, assisting the radiator in cooling the engine. The actual cooling is done by the water outside the engine block.