How to Distinguish Between Semi-Synthetic and Full Synthetic Motor Oil?
2 Answers
Methods to distinguish between semi-synthetic and full synthetic motor oil: 1. Generally, semi-synthetic oil is often labeled as "synthetic type" or "synthetic technology," while full synthetic oil is directly labeled as "full synthetic." 2. Another method is to check for labels indicating PAO and ester oil. Only products that use these two raw materials without blending the first, second, or third base oils are considered synthetic oil. If it contains PAO or ester oil, it must be labeled as "full synthetic oil." Differences between semi-synthetic and full synthetic motor oil: 1. Semi-synthetic oil is based on mineral oil and refined through hydrogenation, while synthetic motor oil is derived from ethylene and propylene dispersed from natural gas in crude oil, refined through complex chemical reactions such as polymerization and catalysis into high-molecular lubricants. 2. Full synthetic oil has a wider temperature range and a longer service life. 3. For the same oil film requirements, synthetic oil has a lower viscosity, while semi-synthetic oil has a higher viscosity compared to synthetic oil. 4. Semi-synthetic oil is mainly used for economical vehicles, while full synthetic oil is primarily used for luxury vehicles. 5. The amount of additives differs, with full synthetic oil containing more additives and semi-synthetic oil containing fewer. 6. Full synthetic oil has better anti-aging stability. 7. Full synthetic oil provides better engine protection. 8. The price of full synthetic oil is higher than that of semi-synthetic oil.
To distinguish between semi-synthetic and full synthetic motor oil from my daily driving experience, I mainly look at the packaging labels. Full synthetic oil is prominently marked with 'Full Synthetic' or '100% Synthetic' on the bottle, while semi-synthetic is labeled as 'Semi-Synthetic' or 'Synthetic Blend.' Sometimes I also pay attention to the API certification code—full synthetic usually meets SN or SP grades, offering more stable performance. But don’t rely on color or viscosity tests; those are unreliable. Semi-synthetic oil might appear slightly cloudier, but the actual fluid is similar. I learned the hard way when I mixed semi-synthetic oil once in winter, causing sluggish engine starts. Since then, I’ve stuck to full synthetic, which has much better low-temperature fluidity. Remember, regularly checking oil quality can prevent engine wear, saving both money and hassle.
