03 2199 Mercedes poor fuel consumption - Baldrick123
I have a three faults on my Mercedes CD220i which I think are linked. I get lots of black/grey smoke on hard acceleration which has been made better by a service including replacing the air filter, but despite blasting it down the motorway it still creates the smoke every 10 minutes of driving.

Also the car only does 42mpg despite it spending much of its life doing 55mph, the handbook says it should do 55mpg.

The third issue is the fuel consumption indicator on the dashboard says it is averaging 58mpg.

Is this a dirty injector fault? I have tried redex but no difference.

All help appreciated