Be careful not to fill your car tank with fuel

Mechanics have said that you should not fill your car tank with fuel until it is completely filled, but that you should leave some free space.
The reason for this is that the fuel pump cabin has a return tube and it is called the return or return line. When your car tank is filled with fuel and the liquid reaches the top of the tank, the return line valve is opened in the fill handle to return the excess fuel to the station, but after that fuel has passed through the counter and charged you for it.
So it is advised not to fully pack to avoid this. In this case, you have paid for a quantity of gasoline and then returned it to the station without charge.
Another tip is to refill early in the morning when the ground temperature is low. Fuel is stored in underground stations.
When the ground temperature is cold, the density of gasoline is higher, and when the temperature rises, the density of gasoline decreases in the afternoon.
And when you buy gasoline in hot times you take it less dense, which means that you pay for one liter for less than a liter.
It is also not recommended to press the trigger of the filler handle until the strongest and fastest level to reduce the amount of steam produced during fuel injection. All fuel pumps have a steam return line. The higher the pumping speed and the more steam, the greater the amount of fuel returned to the pump, and of course after you have paid for it again.
It is also very important advice to avoid filling from the station where there are tanks that fill their underground vents. The reason for this is that pumping the fuel tank into the storage makes the sediment in the station tank seat moveable and not stagnant, which means that this sediment may enter your car tank when you fill it, and this will harm your car.