Can Semi-Synthetic Engine Oil Last for 10,000 Kilometers?
3 Answers
Generally, semi-synthetic engine oil needs to be replaced after about 7,500 kilometers. Below is relevant information: 1. If it is fully synthetic engine oil, it can last for 10,000 kilometers without any issues. This is because fully synthetic oil contains higher levels of additives (TBN), which extends the oil's lifespan. In contrast, semi-synthetic oil has lower additive (TBN) content, resulting in a shorter maintenance cycle. Prolonged use can negatively impact the engine. 2. The main difference between fully synthetic and semi-synthetic oil lies in the fact that fully synthetic oil can operate over a wider temperature range and has a longer service life. For the same oil film requirements, fully synthetic oil can achieve the desired performance with lower viscosity, whereas semi-synthetic oil requires a relatively higher viscosity to meet the same standards. In terms of cost, semi-synthetic oil is definitely cheaper.
As a veteran driver with decades of experience, I've tried pushing semi-synthetic oil to 10,000 km. Honestly, it depends on driving conditions. In stop-and-go city traffic, the oil turns black like coffee grounds by 6,000-7,000 km, losing lubrication efficiency - you'll hear louder engine noise and increased fuel consumption. Once I stubbornly ran it to 10,000 km on a highway trip, only to find slight cylinder wear during disassembly. I regretted not changing it sooner. My advice: check the dipstick every 6,000 km - if the oil appears dark or thickened, change it immediately. Don't risk engine overhaul costs for marginal mileage gains. Regular maintenance is king.
I also tried to save time and money by using semi-synthetic oil for up to 10,000 kilometers. But the results weren't great. Semi-synthetic oil theoretically has a limit of 7,500 km. Beyond that, the oil's protective layer weakens, increasing engine friction, which may cause abnormal noises or malfunctions. I almost caused cylinder wall damage just to save a few hundred bucks on maintenance. Safety tip: If you often drive on highways with smooth road conditions, you might barely stretch it to 9,000 km, but never attempt this with short city drives. Checking is simple: after the engine cools down, inspect the dipstick for cleanliness—stop using if it turns black. Financially, changing oil earlier is much more cost-effective than engine repairs.
