How do we know they arnt over reading? I filled up last night put 59 litres in last night, according to parkers the S3 has a 62 litre fuel capacity, which would mean I had 3 litres of fuel left, I was probably 1 bar into the red (there appears to be 3 bars iirc) and have filled up from lower on the gauge and not put as much in to fill the tank, which means either my gauge is faulty or the petrol station pumps over read i.e. 59 litres was attually 55. Does any one know what measures are in place to prevent such things happening? Are the pumps calibrated or tested on a regular bases?