What is the difference between synthetic and semi-synthetic motor oil?
2 Answers
There are the following differences between synthetic and semi-synthetic motor oil: 1. Semi-synthetic oil: A product purified from mineral oil through hydrocracking technology, it is a mixture of mineral oil and fully synthetic oil in a 4:6 ratio. The purity of semi-synthetic oil is very close to that of fully synthetic oil, but its cost is slightly higher than that of mineral oil, making it an ideal transitional product from mineral oil to synthetic oil. 2. Fully synthetic oil: Fully synthetic oil is a high-grade product among motor oils. It is derived from ethylene and propylene dispersed from natural gas or gas from crude oil, and then undergoes complex chemical reactions such as polymerization and catalysis to form a lubricating fluid composed of large molecules.
The biggest difference between synthetic and semi-synthetic motor oils lies in their base oils. Synthetic oil is fully man-made with more uniform molecular structures, offering better stability at high temperatures and superior low-temperature fluidity. This results in quieter engine operation and extended oil change intervals up to 10,000 km or longer. Semi-synthetic oil is a blend of mineral and synthetic oils, delivering balanced performance at a significantly lower price point, making it ideal for daily urban commuter vehicles. For drivers frequently stuck in traffic, I believe semi-synthetics offer better value for money, though full synthetics provide more comprehensive protection during long highway drives. Additionally, synthetic oils can slightly reduce fuel consumption due to lower friction, while the difference with semi-synthetics is negligible under normal driving conditions – the vehicle's age matters most. Older cars typically suit semi-synthetics better as overly thin oils may cause leaks. My personal compact car runs on semi-synthetic year-round, which proves perfectly adequate.
