Today, BMW 525li accidentally added 93 # gasoline, which used to be 97%. Will it affect the engine or the car? I will run the expressway tomorrow.

# refers to the octane number index of gasoline. 90, 93, 97, 98.

The so-called 97 # gasoline is 97% isooctane and 3% n-heptane. If the compression ratio of the engine is high, high octane gasoline should be used. If the compression ratio is high,

Gasoline (1 1 sheet) High and low octane gasoline can cause abnormal combustion, leading to knocking, fuel consumption and driving fatigue.

The label of gasoline only indicates the octane number of gasoline, and different labels of gasoline should be selected according to the different compression ratios of engines. A mid-range car with a compression ratio of 8.5-9.5 generally uses 93 # gasoline; Cars with compression ratio greater than 9.5 should use 97 # gasoline. The compression ratio of domestic cars is generally above 9, and it is best to use 93 or 97 gasoline.

If the engine with high compression ratio uses low-grade gasoline, the cylinder temperature will rise sharply, the gasoline will burn incompletely, and the machine will vibrate strongly, thus reducing the output power and damaging the parts. If the engine with low compression ratio insists on using high-grade engine oil, it will have the phenomenon of "delayed combustion", that is, it will not reach the auto-ignition point even if it is pressed on the head, and it will also have the phenomenon of incomplete combustion, which is not good for the engine.

The higher the grade of the vehicle, the higher the requirements for fuel quality. For example, for mid-to high-end cars with more than 300,000 yuan, only No.95 or No.97 gasoline can be added. Here, No.95 and No.97 only represent the octane number energy in gasoline, but it does not mean that No.97 gasoline is cleaner than No.93 gasoline. High-end cars, on the cleanliness of gasoline requirements are extremely high. If the label of gasoline is not enough, the impact on vehicles will soon be shown, such as the phenomenon of acceleration weakness immediately after refueling; If there are too many impurities in gasoline, it will take some time to reflect the impact on the car, because the increase of carbon deposit or gum will affect the driving of the car to a certain extent.

The state has strict standards for motor gasoline. It not only requires gasoline to have a certain octane number (commonly known as gasoline label), but also has strict regulations on the content of various chemical components of gasoline. If the olefin content is too high, the car will not burn completely, resulting in a gelatinous substance that accumulates in the intake manifold and valve guide. When the engine is at normal working temperature, there is no abnormality; When the engine is turned off and cooled for a period of time, the glue will stick the valve in the valve guide. At this time, when the engine is started, the phenomenon of valve jacking will occur.

The higher the label, the better. The gasoline grade should be reasonably selected according to the compression ratio of the engine.