on a short (about 25 mi) drive this past weekend from Northbrook IL to Chicago down US 94 (comfort, AC on etc.), resetting the trip computer at the begggining of the drive gave us 35 US MPG at an average speed of about 65 MPH driving . clearly this is only a short drive and hwy only, but for a non-diesel engine to put out 35 mpg at 65mph while crusing on the hwy is amazing in my book and makes the x3 with the N20 a great hwy cruiser.
we got close to 30 mpg on the drive from the factory in SC to Chicago, and I think our average speed over 800 mi was faster (more like 70 mph, but we went as fast as 90 mph in spurts)
2013 X3 28i, AW, Chestnut, Sienna, ZAP, ZCV, ZCW, ZDH, ZPP, rear view, park distance, cargo net (Wife's) (Pics and story
2010 Porsche Boxster S (Mine)