What is the difference between mineral oil and semi-synthetic oil?
2 Answers
Mineral oil and semi-synthetic oil differ in that: mineral oil is refined from petroleum as a base and then mixed with additives; semi-synthetic oil is synthesized through chemical methods and then mixed with additives. Automotive oil is a lubricant for the engine system, possessing certain anti-oxidation, anti-wear, and anti-corrosion properties. The functions of oil are: 1. As a lubricant, it reduces friction and damage between moving parts; 2. As a coolant, it absorbs heat generated in the engine combustion chamber and piston top, cooling the engine and protecting it from overheating. 3. As a sealant, it fills the space between the piston rings and cylinder liner to prevent the leakage of combustion pressure.
Mineral oil is a natural oil directly refined from crude oil, which is inexpensive but has average performance. It tends to thicken or thin out under high or low temperatures, affecting engine protection, and has a short replacement interval, typically requiring a change every 5,000 kilometers. I drove an older car for several years, and when using mineral oil, the engine noise was loud, and startup was slow, especially in winter, as the oil's fluidity felt poor. Semi-synthetic oil is a blend of mineral and synthetic oils, enhanced with artificial additives, offering better fluidity and stronger oxidation resistance, capable of lasting over 7,500 kilometers between changes. In the long run, the cost is similar. After switching to semi-synthetic oil, my engine became quieter, and fuel consumption slightly decreased, making it suitable for owners who frequently drive on highways. If budget is tight, mineral oil suffices for daily driving, but for those prioritizing engine longevity and smoothness, semi-synthetic is the upgrade choice.
