Gasoline, which is formed by the chemical processes of crude oil, is still one of the largest energy sources for automobiles. Gasoline used for vehicles has some properties and these vary according to the structure, characteristics and operating conditions of the engine. Among the properties of gasoline is a specific gravity. The specific gravity of gasoline is between 0.70 and 0.80. Since its high specific gravity will increase the boiling point of gasoline, it makes it difficult to start, negatively affects the operation of the engine at low temperatures and speeds. On the other hand, if the evaporation pressure of gasoline is low and the weather is cold, it makes it difficult for the engine to start. High vapor pressure and high air temperature can cause vapor blockage in the fuel lines. Therefore, the pressure of the gasoline vapor is in summer and winter, that is, twice a year, should be checked. The distillation feature of gasoline shows the evaporation ability of gasoline. The distillation temperature is highly effective on the operation of the engine. Starting the engine at 10% distillation temperature and in cold weather affects factors such as the acceleration of engine oil contamination. The higher the octane number, which shows the resistance of gasoline against knocking, the less chance of self-ignition of gasoline and there will be no knocking.