What is semi-synthetic oil?
Or maybe a semi-synthetic engine oil?
In this section: 6 articles
Semi-synthetic engine oil is made from a blended base, where the synthetic component makes up 30-50%, and, correspondingly, the mineral component makes up 50-70%. This kind of oil really does have much better characteristic stability than mineral oil, but falls short of synthetic.
Semi-synthetic engine oil is usually recommended for use in modern engines with high mileage, once oil burn-off starts to increase. In situations like this, semi-synthetic is the optimal choice, since the odds of finding a semi-synthetic oil that meets all the engine manufacturer's requirements are fairly high, unlike with mineral oil.