Which engine oil is better, Shell, Mobil or Castrol?

The most prominent feature of shells is cleanliness. After the engine is used for a period of time, it is easy to produce sludge and carbon deposit. Because high-precision cars need to be kept in good condition, it is best to choose a clean shell. But its disadvantage is that it is not durable and needs to be replaced frequently. For Mobil, it likes to follow the trend of technology and continue to develop synthetic oil technology. The biggest advantage of synthetic oil is that it is not easy to degrade and the oil change cycle is long. At the same time, it has good sports performance and high temperature resistance. Although it sounds like a lot of benefits, it is actually produced by a technology, that is, a base oil called polyene developed by Mobil itself. This is a patented technology of ExxonMobil, and the English abbreviation of the local language is PAO. This base oil is catalyzed by the polymerization of ethylene and propylene in coal gas and natural gas. For some economical cars, you can choose Mobil, or change the oil once every six months, or change the oil once every 654.38+0.5 million kilometers and 654.38+0.5 million kilometers. If you cooperate with Mobil's longevity machine filter, you only need to change the oil once every 25 thousand kilometers, which is quite durable. Therefore, friends who use Mobil oil suggest replacing it every 5000 kilometers in 4S shop. Finally, when it comes to Castrol, its deepest impression is the endorsement of various stars, but this is obviously not a characteristic technology. Castrol is characterized by its good protection against engine cold start. In principle, its low-temperature fluidity will become better. In addition, even if the car stalls, because only a small part of the engine oil sticks to the engine, it will not completely flow back to the oil pan due to gravity. Therefore, Castrol is a good choice in a relatively cold place, or an old model with difficult cold start.