I use my X5 as my DD, which I am sure most of us do. I read, prior to buying, how bad or less than good gas mileage was. Coming from a Toyota 4Runner, after driving the X5, I will say that it wasn't as bad as I thought.
Well, I noticed something recently. My wife is Pregnant, and really does not like the bumpiness of the ride. It seems to be a job to manage feathering the gas and the brakes so as not to jerk her too badly as well, so I came up with something. I use the CC getting around and have noticed a better response from her regarding the stop and go aspect - she still doesnt like the stiff ride, makes our baby bounce around.
WEll, I always clear out the BC so I can see a new set of info for mpg, mph, and miles left. On the way home from getting gas, I noticed that I had an avg mpg of 17, with and mph avg of 28. Not bad I thought. So i set up parameters of not exceeding 10 MPH over the designated speedlimit where I am at, which should at least ensure that I don't piss off the other drivers, and using the cc to see what happens. So far, I am at about 78 miles and 17.6 mpg - ALL City. I will say that it seems less of an enthusiastic way to drive this vehicle, and I sure as hell did not buy this for mileage...just a little experiment to myself and thought I would share the results. I DO enjoy Sport Mode on my own, and having fun with my vehicle, but for this tank of gas, I will do my experiment and fill you in with final results. Just thought some of you might beinterested or at least give you 2-3 minutes of reading over your coffee.

G