Manipulated petrol pump??

On Saturday I filled up at an Engen garage in Edenvale. My on board computer indicated 70 kms to empty which, at an average consumption of 8 kms/l would mean I had about 5.8 liters remaining . My petrol tank has a 70 liter capacity yet the pump dispensed 75.83 liters. HOW???? I can only speculate.<br> <br> I have not approached the dispensing station concerned because I feel that it needs a surprise investigation by the principal. The customer care facility on the Engen website as well a the phone line seems to be for THEIR customers ie the petrol station, and not for the motorist. <br> <br> I would like see Engens response before I take it any further. Proof is available