The most important thing is engine oil, which means that all BMWs are made in synthetic engine oil. I tell you that there is no such brand. The best engine oil on the market at present is Mobil engine oil. And shells. But there are many fakes. You have to believe this sentence, there is no such thing as falling off the pie, greedy for petty gain and losing money. 4S is to earn after-sales money. 4S sells 500 yuan of oil, and you can get it for 300 yuan outside, but do you dare to take it? You can't tell whether it's true or not unless your own brother is selling it.