Can You Mix Different Engine Oils If the Level Is Low?
4 Answers
No, you should never mix different engine oils. Engine oil is the lifeblood that maintains the engine's health. It cools and lubricates the engine components, ensuring the normal operation of moving parts, reducing friction, lowering temperatures, and minimizing wear. Improper use of engine oil can not only shorten the engine's lifespan but may even lead to engine failure. Here are some relevant details: 1. The vehicle's manual specifies the maximum oil change interval, but the first oil change for a new car should occur after a shorter mileage. After that, the oil should be changed every 5,000 to 10,000 kilometers. If the car is used infrequently, the oil should be changed based on time—typically, dealerships recommend changing it every six months. In short, the oil change interval should not be too long, as oil degrades and depletes over time. 2. Choosing the right oil involves two steps: First, select the appropriate oil grade as specified in the vehicle's manual. If the exact grade is unavailable, a higher-grade oil can be used, but never a lower-grade substitute. Second, choose the viscosity grade based primarily on the ambient temperature. During hot summers in Changsha, for example, drivers can opt for summer-grade oils ranging from SAE 20 to SAE 40. To ensure proper lubrication, select the lowest possible viscosity oil based on the operating temperature range, engine temperature, and actual vehicle condition. 3. Since oil tends to thin when heated, its oxidation resistance weakens, making it prone to degradation and even causing severe issues like bearing seizure. Therefore, regularly check the oil level and quality, and replace it promptly. Additionally, avoid mixing oils from different brands. It's also advisable to choose multi-grade oils, as they offer better engine protection due to their efficiency, longevity, and cost-effectiveness.
When I was driving that old Ford before, I encountered low engine oil and in a panic, I added some off-brand oil given by my neighbor. As a result, the engine noise increased and it started smoking. Later, the mechanic told me that different engine oils have different additives, and mixing them can cause chemical reactions, leading to poor lubrication and accelerated wear of parts. It's best to regularly check the oil level when the engine is cold by pulling out the dipstick to see the scale. If the oil level frequently drops, there might be a leak. If you really need to add oil, make sure to use the same brand and model. In a pinch, mixing in some similar mineral oil can hold you over, but change to new oil as soon as possible. Otherwise, the engine might fail prematurely, and that would be a huge loss. After years of car maintenance, I've learned a lesson: don't take small issues lightly.
Having played with cars for over a decade, I believe mixing engine oils should be avoided whenever possible. Different types of oils, such as fully synthetic and mineral oils, have varying additive compositions that may conflict, leading to clumping and sedimentation, which compromises engine protection. In emergencies during long trips when oil levels drop, you can temporarily add oil with a similar viscosity—just ensure it's free of impurities and pour it slowly using a funnel. It's best to develop a habit of checking the oil level monthly, keeping it at the midpoint to minimize surprises. If your car burns oil excessively or has severe leaks, head to a repair shop immediately instead of relying on mixed oils as a quick fix.
From a safety perspective, mixing engine oils carries significant risks. Insufficient lubrication can cause the engine to overheat and increase friction, potentially damaging critical components like the crankshaft and compromising driving safety. If the oil level is low, always measure it accurately before adding more—using the same type of oil is the best solution. In emergencies, mixing oils with similar base properties can serve as a temporary fix, but avoid blending multiple brands. Drive to a mechanic promptly to diagnose the root cause, which could be aging seals or other malfunctions. Regular maintenance shouldn’t be neglected.
