Collected my (new to me) E63 S estate 2 weeks ago ... not managed to drive it a great deal as yet but saw a 22mpg figure commuting to work on Friday. Then went to meet some friends in York saturday and ended up sat in traffic for ages ... my 20+ mpg turned into 13mpg by the time I'd parked up. But hey, I knew it would be a thirsty beast.
Hopefully I'll squeeze 20mpg-ish ave going forward.