Can Semi-Synthetic Motor Oil Last for 8,000 Kilometers?

[DiVincent]

Most semi-synthetic motor oils can last for 8,000 kilometers. Here is a detailed introduction about semi-synthetic motor oil: 1. Overview: Semi-synthetic oil (Semi-Synthetic Lubricant) is a type of motor oil. It is formulated using semi-synthetic base oils, specifically Group III base oils, which are refined from mineral oil through hydrocracking technology. 2. Composition: It is a blend of mineral oil and fully synthetic oil in a ratio of 4:6. The purity of semi-synthetic oil is very close to that of fully synthetic oil, but its cost is slightly higher than mineral oil. It serves as an ideal transitional product from mineral oil to synthetic oil.

[ODelaney]

My old car had been using semi-synthetic oil, and I even tried changing it at 8,000 kilometers. To be honest, it felt fine. When driving mostly on highways, the oil quality didn’t change much—the engine ran smoothly with no noticeable increase in noise. However, in heavy city traffic with frequent stops, the oil degraded faster. I’d recommend checking it every 7,500 km under such conditions. It’s best to regularly use the dipstick to check if the oil level is sufficient and whether the oil has turned dark and sticky. After all, prolonging oil changes too much could lead to engine wear or reduced fuel efficiency. Ultimately, following the manufacturer’s manual is the safest bet—saving a little on oil changes is trivial compared to the major hassle of engine repairs.

[VonMartin]

Many car owners ask about this during repairs. Semi-synthetic oil can theoretically last 8,000 km, but actual driving conditions have a significant impact. For example, in mountainous or dusty areas, the oil gets dirty faster and needs to be changed after around 7,000 km. If you drive smoothly on highways, 8,000 km might be fine. The key is to check the oil's aging level. A simple method is to extract some oil and drip it on paper to check for debris or unusual odors. Extending the interval to save money is tempting, but if delayed too long, the oil film thins, increasing the risk of engine overheating. To be safe, it's best to change it every 7,500 km.

[McMatthew]

Whether semi-synthetic oil can last 8,000 kilometers depends on driving habits and environment. For example, gentle highway driving extends oil life, while aggressive acceleration or frequent short trips with cold starts degrades oil faster. From a cost-saving perspective, extending oil change intervals may seem convenient, but long-term engine wear could lead to higher repair costs. Environmentally, premium oil reduces waste, but don't overextend intervals. Regularly check oil levels and filters for safety.