I'm getting about 20 around town and 28 on the highway, closer to 29 with eco pro on.There is only about 500 on the odometer, so it's a small sample, but it may do better when the engine is completely broken in.
For comparison, my previous 335 coupe was rated at 24-25 on the highway, but after a couple years it was routinely getting 28-29.
2013 X1 35 MB/Black/ULT/CW/HK/Lighting/Paddles
2009 335i xDrive Coupe Black/SB MT/SP/PP/CWP/PDC/Logic7/iPod
2004 325iT SB/Black SP/PP/CWP/PDC/HK/Step/Xenon
2006 X3 SG/Black PP/CWP/Xenon
2006 330i SG/Terra MT/SP/PP/HS/CA
2004 330i SG/Black MT/SP/PP/HS (my
2001 325i SG/Black MT/SP/PP/SF/Xenon