Can Different Types of Engine Oil Be Mixed?
3 Answers
It is not recommended to mix different types of engine oil. Different brands and grades of engine oil contain varying base oils and additives, which may lead to incompatibility or chemical reactions when mixed. Therefore, engine oils of different specifications should not be mixed. However, in special circumstances, temporary mixing may be allowed, but the entire oil should be replaced as soon as conditions permit. Engine oil, also known as motor lubricant, serves multiple functions such as lubrication and wear reduction, cooling, sealing and leak prevention, rust and corrosion protection, and shock absorption. Engine oil consists of two main components: base oil and additives. The base oil is the primary component, determining the fundamental properties of the lubricant, while additives compensate for and improve the shortcomings of the base oil, providing additional performance benefits and making them an essential part of the lubricant.
Mixing different engine oils is actually not very wise. With years of driving experience, I've seen friends experience louder engine noises after mixing oils. The viscosity and additives of different oils may conflict, leading to reduced lubrication effectiveness. Even within the same brand, mixing synthetic and mineral oils can make the oil molecules unstable and increase friction. Adding a little as an emergency measure when oil is critically low is acceptable, but you should replace the entire oil as soon as possible. Long-term mixed use can accelerate wear and lead to higher maintenance costs. It's recommended to choose oils of the same specification, such as 5W-30, to avoid this risk.
From a safety and reliability perspective, I do not recommend mixing engine oils. Different oil additives may react and form sediments, potentially clogging oil passages or increasing wear. Once, when I delayed an oil change, fuel consumption noticeably increased. After mixing oils, the engine temperature abnormally rose, affecting overall performance. It is advisable to regularly check the oil level and condition. If mixing is unavoidable, a small amount for short-term use is acceptable, but priority should be given to using the manufacturer-recommended oil to ensure stable engine operation.
