What is Synthetic Engine Oil and What is Semi-Synthetic Engine Oil?
2 Answers
Semi-synthetic engine oil and full synthetic engine oil are two classifications of engine oil: full synthetic oil can be used in a wider range of temperatures and has a longer service life; semi-synthetic engine oil is a lubricant formulated from Group III base oils, which is a product refined from mineral oil through hydro-cracking technology. Specifically, it is made by mixing mineral oil and full synthetic oil in a 4:6 ratio and adding some additives. Below is relevant information about full synthetic and semi-synthetic engine oils: 1. Different base oils: Semi-synthetic engine oil uses Group III base oils; full synthetic engine oil is a mixture of Group III, IV, and V base oils. 2. Different replacement cycles: Semi-synthetic engine oil should be replaced every six months or 7,500 kilometers during use; full synthetic engine oil should be replaced every year or 10,000 kilometers during use. 3. Different usage temperatures: Full synthetic engine oil can be used in a wider range of temperatures. Under the same working conditions, full synthetic oil can protect the engine with lower viscosity, while semi-synthetic engine oil has relatively higher usage requirements. 4. Different applicable vehicle conditions: Semi-synthetic engine oil is more suitable for economical small-displacement vehicles with smooth driving; full synthetic engine oil can be used under various harsh and severe conditions or for those pursuing engine maintenance. 5. Different additives used: Full synthetic engine oil uses additives with high TBN content, which extends the oil's life and cleans the engine; semi-synthetic engine oil uses additives with low TBN content, shortening the oil maintenance cycle and producing sulfurized ash.
Synthetic oil sounds fancy, but it's essentially scientists tinkering in the lab, completely artificially modifying molecular structures based on petroleum. The molecular arrangement of this stuff is as neat as military parade formations, with ultra-strong low-temperature fluidity that ensures smooth starts even in sub-zero temperatures. It remains stable at high temperatures too, resisting oxidation even during prolonged high-speed driving. What I love most is its cleaning capability, significantly reducing engine carbon buildup. Though the price is indeed steep, considering it can last over 10,000 kilometers between changes makes it cost-effective. Semi-synthetic, on the other hand, is like a 50% lab formula mixed with 50% mineral oil – better than pure mineral oil yet cheaper than full synthetic, perfectly adequate for daily city commuting.
