How to Know When the Car is Fully Fueled?
2 Answers
At the calibrated capacity of the fuel tank, there is a liquid level control valve. When the liquid level reaches the opening of the level pipe, the fuel blocks the venting exhaust during refueling. The fuel level will accumulate in the refueling filler pipe, triggering the pump to automatically shut off. Additionally, the fuel dispenser nozzle at gas stations is equipped with a trigger mechanism that can automatically stop the flow.
Having driven for over a decade, the most intuitive signal when refueling for me is the sound of the fuel nozzle automatically clicking off. When the fuel level submerges the air vent hole of the nozzle, the change in air pressure causes it to automatically shut off, indicating a full tank. For some older car models, you need to observe the fuel tank opening – when gasoline foam reaches the edge of the filler neck, it means the tank is full. Remember not to force extra fuel just to round up the amount, as this not only wastes money but can also damage the emission system if gasoline overflows into the carbon canister. I learned this the hard way – overfilling in summer can cause excessive tank pressure due to thermal expansion. Nowadays, gas stations are equipped with precise metering devices, ensuring that after the nozzle clicks off, the tank retains just enough safe expansion space.
