Many of us are not aware that the petrol kiosk pump has a return pipe-line (in Pink ). When the petrol tank (in the car) reaches full level, there is a mechanism to trigger off the pump latch and at the same time a return-valve is opened (at the top of the pump station) to allow excess petrol to flow back into the sump. But the return petrol has already pass through the meter, meaning you are donating the petrol back to SHELL/CALTEX/MOBIL/ PETRONAS.

Already petrol bunk people cheat the consumers with many tricks. But we would have not aware of this trick right? When technology grows the tricks to steel will also grow. Apply the Newtons law here. “Every action will have an equal & Opposite reaction“.