[WapCar] The fuel label represents the octane number, the higher the octane number, the better the anti-knock performance. Generally, the fuel label is directly related to the engine compression ratio, that is to say, the higher the compression ratio, the higher fuel label gasoline should be used. Of course, this is not absolute, some engines with higher compression can use relatively low-grade gasoline through post-adjustment and special structural design, the advantage of this is that it provides convenience to consumers and reduces the cost of car use.