Highest I have ever gotten on my RWD M340i is low 20's on a 300 mile road-trip. I average mid to high teens. Always astonished to see the rather high MPG people claim here.
Then again, it could be my driving style because I went for a drive the other day and noticed I was basically either at red-line or bouncing off the limiter which may explain my numbers. It's all good though, I didn't get this car to drive it like grandma.
