Bad Fuel Consumption

To Whom it May Concern,<br> <br> I purchased a new Merc C180 in 2012 believing this to be the best car for my wife Fuel efficient, safe and a lovely automatic to drive. Well she fell in love and we have had no issues other than the high fuel consumption. <br> <br> Shortly after purchasing the new Merc C180 in 2012 we both noticed that the fuel consumption to be extremely high versus the advertised +/- 6.7L per 100km urban, we swapped cars to see if it was purely driver related and neither of us could achieve less then an average 11L per 100km on a tank. Vehicle was sent in for evaluation nothing out of the ordinary was picked up. I have raised this concern several times.<br> <br> How can we correct this or is the listed figures that far out?<br> <br> <br> <br> <br>