High fuel consumption on 2006 S6

[DAVID ROSE]

Can anyone comment on recent high fuel consumption on my 2006 S6

 

[DGSdale]

How long is a piece of string? It's a very difficult question to answer even with some decent information! Tyre pressures? Roof rack? Needs a good service? Brakes binding? MAF? CTS?
BTW - unless your car was sitting around for some time in a dealers before being first registered, then it's a C6