Is it possible to determine the grade of gasoline just by looking at the compression ratio of the vehicle?
(1) Everyone knows that gasoline motorcycles use low-grade fuel for low compression ratio and high-grade fuel for high compression ratio, but this is not absolute! It does not mean that a high compression ratio must use high-grade fuel, and there is no inevitable relationship between the compression ratio and the choice of fuel grade.
(2) First, the mixture will generate heat due to the fusion reaction during compression. The higher the pressure in the cylinder, the higher the heat. Note that the pressure in the cylinder is said here, not the compression ratio. According to the pressure in the cylinder, the fuel with the matching label is selected, which is often referred to as No. 92 and No. 95.
(3) I believe everyone knows the difference between fuels of different grades, which is the content of octane number. A simple explanation is that low-grade fuel is easier to ignite, has a lower ignition point, and is less stable than high-grade fuel. Not to say that the oil quality is different. Therefore, higher cylinder pressure has a higher contribution to the liter of power and fuel economy of the engine.