Can the same model of engine oil be mixed?
2 Answers
Same model of engine oil can be mixed, but it is not recommended for long-term use. Functions of engine oil: Engine oil is the lubricating oil for engine operation. It can lubricate, clean, cool, seal, and reduce friction for the engine. It plays a significant role in reducing the wear of engine parts and extending their service life. Oil filter: Engine oil contains a certain amount of gum, impurities, water, and additives. During engine operation, metal shavings generated by friction of various parts, impurities inhaled from the air, and oxides in the engine oil are all filtered by the oil filter.
I've been driving for twenty years and often encountered low oil levels. Mixing oils of the same specification is a common practice for me. In fact, as long as the viscosity is the same and the additives are similar, the lubrication effect remains largely unchanged, and there's no significant harm to the engine. I've done it several times myself—for example, mixing different brands of SAE 5W-30 synthetic oil with the same specifications—and the car still ran smoothly. However, be mindful of brand differences. While mixing is possible, it's best to use oil from the same bottle or batch to avoid minor additive reactions that could cause deposits. Regularly checking the dipstick and maintaining stable oil levels can save a lot of trouble. For everyday maintenance, small amounts of mixed oil are acceptable, but avoid frequent or random top-ups—engine longevity comes first.
