Can the same model of engine oil be mixed?
4 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.
As a seasoned mechanic with years of experience, I've seen countless car owners mix the same type of engine oil, and the overall risk is minimal. These oils are designed with compatibility in mind, with uniform viscosity standards, so the engine protection capability remains even when mixed. Occasionally, minor issues may arise, such as potential conflicts between additives from different brands leading to sludge buildup, but the probability is low. I recommend that mixing is acceptable in emergencies, but sticking to the same oil long-term is better. Try to maintain regular oil change intervals and don't delay too long just to save money. After mixing, remember to monitor oil pressure and noise—discontinue use if abnormalities occur. Simply put, reasonable mixing is a cost-saving approach, but don't overlook the small details.
I'm quite traditional when it comes to car maintenance. With ample driving experience, I remain cautious about mixing engine oils. While theoretically feasible with the same model, I avoid mixing whenever possible, fearing minor differences might affect lubrication. For instance, variations in additive formulations could lead to chemical reactions when mixed, potentially degrading performance. My old car once had minor issues due to mixed oil usage. Therefore, I prefer using a full bottle of oil at a time, saving the remainder for backup. If mixing becomes necessary, monitor engine response and fuel consumption closely, and avoid high-temperature driving conditions. For safety's sake, sticking to a single oil type is most reliable, especially for high-mileage vehicles that require extra caution.
