Sooty Exhaust

I've had my 2014 328I for just over a year now.

I noticed on some longer drives (over 200 miles) that the exhaust pipe is always sooty. It's enough that it leaves a mark on my finger when I run it along the pipe exit.

My past experiences with all my cars is that the pipe would be a light gray without any carbon soot.

Is this normal for this car. Is it a characteristic of the fuel system that doesn't allow it to 'lean' out on the highway?



Thanks in advanced.