Lat2182

My C200 w206 is consuming 14 to 15 l/100km, the dealer made an upgrade to the ECM but stills the same, I live in a high altitude city of 2600 meters above sea level, please yoyr help of what else can I do in order to reduce the fuel consumption to normal levels.

RoyalCanuck

This is well above the advertised mileage of 9.9 L/100km (city). You won't be able to make it more efficient.

giovane

So weird. In US the city consumption for a C300 (25mpg) is around 9,41lt/100km and it’s very achievable.