Bumping; '06 330Ci Steptronic here, I always fill up with 98; current tank is 12.4 L/100, avg speed 36.5km/h. I'd estimate about 5% hard driving, 20% spirited driving, 75% loping around both in the city and on highway. Before the hols in peak hour driving it was more like 13-13.5L/100, which is probably about right, given my old '99 328Ci used to do about 11.5 in city, but it was a manual. The 330 is making my old E38 740iL look not too bad though, it used around 16-18L/100 in the city - just shy of 2 tonnes and 210kW from a 4.4 litre.
Also posting for the record, Redbook states the following manufacturer claims for City / Highway / Combined, for an '06 330Ci:
Manual: 10.0 / 6.2 / 9.1
Auto: 10.5 / 6.6 / 9.6