Considering 2012 A8 3.0tdi. Feedback on real world MPG please

[FortyPlus]

Hello all
I am new on this forum, considering a nearly new (2012) A8 3.0tdi (250hp).

I am coming form a few VW Phaeton over the past 5 years, so a similar engine, but at 2370kg, V 1840 kg that's more than 500kg difference in the weight, and an 8 speed Vs 6 speed so I will expect much better economy then in the VW's (long term average ~30mpg) up to 35 on the motorway.

1) What is experience on the latest cars for real world economy?
2) What options are essential : I see comfort sears as essential, but what else is needed on the "executive" model?

Any other tips.
Many thanks in advance.
Hugh

[Guest 2]

My 3.0 TDi A6 is getting 17-23mpg around own and anything from 32-41mpg on a motorway run.