This standard stipulates that the rated capacity of a car fuel tank should be controlled within 95% of the maximum capacity of the fuel tank. This means that the actual capacity of the fuel tank is greater than its rated capacity, in order to ensure that there is a certain safety margin in the design of the fuel tank to cope with the thermal expansion and contraction effects of the fuel, thereby ensuring driving safety. In addition, the fuel tank of a car is not a standard measuring instrument, and its actual capacity will vary under different temperatures and pressures inside the tank. Therefore, it is impossible to determine the accuracy of the fuel dispenser's measurement based on the rated capacity of the fuel tank.
In addition, the national mandatory standard GB18296 also stipulates that ordinary cars can usually add an additional 10% to 15% of fuel volume in addition to the marked volume of the fuel tank, taking into account the volume of the oil pipes from the fuel tank to the fuel port and from the engine to the bottom of the fuel tank. This further indicates that additional capacity was considered in the design of the fuel tank to ensure that it can accommodate more fuel in actual use.