Which is Better: Fully Synthetic or Semi-Synthetic Engine Oil?

[AngelinaAnn]

Fully synthetic engine oil is better. Here is an introduction to the differences between semi-synthetic and fully synthetic oils: 1. Source: Semi-synthetic oil is refined from mineral oil using hydro-cracking technology; fully synthetic oil is derived from ethylene or propylene dispersed from crude oil or natural gas, and then undergoes complex chemical reactions such as polymerization and catalysis. 2. Oil quality: Semi-synthetic oil is a semi-synthetic base oil; fully synthetic oil is the highest-grade oil among engine oils. Below is additional information on the functions of engine oil: 1. Lubrication: There is rapid relative sliding between the piston and cylinder, as well as between the main shaft and bearing bush. To prevent excessive wear of parts, an oil film needs to be established between the two sliding surfaces. 2. Auxiliary cooling: Due to its low specific heat value and presence inside the engine, engine oil itself does not have a cooling effect. 3. Cleaning: High-quality engine oil can carry carbon deposits, sludge, and worn metal particles from engine parts back to the oil tank through circulation, washing away dirt generated on the working surfaces of parts via the flow of lubricating oil.

[MacAlaina]

To be honest, I think engine oil selection depends on personal driving habits. Having driven for over a decade myself, full synthetic oil offers superior protection and durability, especially ensuring smoother engine starts in winter and preventing cold-start wear. It can last 10,000 to 15,000 kilometers before needing an oil change, which actually saves money in the long run and reduces time spent on maintenance. Semi-synthetic oil is cheaper and suitable for older cars or owners who don't commute much, but it provides less protection and requires changes every 7,000 to 8,000 kilometers—it's not ideal for frequent long-distance or highway driving. Overall, for new engines or those who drive aggressively, full synthetic is the better choice—cost-effective and excellent for engine protection.

[FinnLynn]

For a car enthusiast like me, full synthetic oil is a must! It provides top-tier protection for high-revving engines, with more uniform molecules that resist thinning, ensuring smoother acceleration and better wear resistance. Having driven sports cars, I've found that semi-synthetic oil tends to have unstable viscosity under aggressive driving, accelerating sludge buildup and shortening engine life. Full synthetic extends oil change intervals to over 12,000 miles, reducing waste oil disposal for better environmental friendliness. Though pricier, this investment is worthwhile for engine health and performance gains. If your car is a regular family model, semi-synthetic may suffice to save costs—just don't expect robust protection.

[OliviaMarie]

As a budget-conscious car owner, I recommend semi-synthetic oil for better cost-effectiveness. It's significantly cheaper, saving you 100-200 yuan per oil change compared to full synthetic. My older car has used it for years with no engine issues. For regular commuting and driving, changing it every 7,000-8,000 kilometers is sufficient. While full synthetic offers better longevity (requiring changes every 10,000+ kilometers), the price difference isn't justified for my needs. The key is choosing based on your vehicle's age and driving habits—don't blindly follow the full synthetic trend. Cost control should come first.