Semi-Synthetic or Fully Synthetic Engine Oil?

[HadleyLee]

Using fully synthetic engine oil is generally better for vehicles. Here are the key differences between semi-synthetic and fully synthetic engine oils: 1. Base Oil Differences: Semi-synthetic oils use Group III base oils, while fully synthetic oils are blended from Group III, IV, and V base oils. Fully synthetic oils use higher-grade base oils compared to semi-synthetic oils. Fully synthetic oils offer superior engine cooling and flow characteristics, making them ideal for turbocharged engines which have more complex structures and require better lubrication. 2. Replacement Intervals: Semi-synthetic oils typically need replacement every 6 months or 7,500 kilometers, whereas fully synthetic oils can last up to 1 year or 10,000 kilometers. The actual replacement interval may vary depending on specific conditions. Fully synthetic oils also have better cleaning properties and oxidation resistance than semi-synthetic oils, allowing for longer replacement intervals of about 1 year or 10,000 kilometers. 3. Temperature Performance: Fully synthetic oils perform better across a wider temperature range. Under the same operating conditions, fully synthetic oils can protect the engine with lower viscosity, while semi-synthetic oils have more stringent requirements. For older engines with some wear, semi-synthetic oils, being more viscous, can better coat engine components, providing protection and reducing wear.