Many of us are not aware that the petrol kiosk pump has a return pipe (in pink). When the petrol tank (in the car) reaches full level, there is a mechanism to trigger off the pump lat6ch and at the same time a return- valve is opened (at the top of pump station) to allow the excess petrol to flow back in the pump. But the return petrol has already passed through the petrol meter, meaning your car donating the petrol back to SHELL/CALTEX/MOBIL/PETRONAS
