I am considering to buy a A8 TDI 4.2 or a 3.0 year 2007-2009 so the "old model"!!!

Can anybody advise me their experience of fuel consumption?

I know, many of you will say: "if you buy a A8, why do you wonder about fuel".
But I am I drive about 20.000km a year and it is a issue in the overall cost of owning a large Audi

My currently RS6 I can get up to 10km/l, driving really economically. At the moment I am doing 8,5-9km/l in the RS6 when driving 80% highway at 110km/h and rest city/major roads.
And in my past I have been able to get most of my cars to "over-perform".
A VW Touran TDI 140hp 18km/l
A VW Transporter TD 105hp at 16km/l
A Audi S8 V8 12km/l

I know the spec. sheet says 7.2l/100km. But what is your experience, driving mixed roads, and highway at 110km/h or 65miles/hour??

And service cost I know, I already had a S8 and the currently RS6, but I have to say, they have not cost me a lot. I get many parts at EBAY and use the local mecanic for the usual service and only let Audi touch the car when it is something special.

 

Nobody??