I'm pretty sure the 2011 cummins don't smoke at all unless you get a full delete kit and a smarty or other programer and then they still don't smoke like a 5.9 cummins

 

I wonder if they are burning efficiently........

 

Hell, you can make any diesel roll coal with a simple plastic bag and a zip tie.

Step one : Place Plastic bag over intake filter.

Step Two : Zip tie bag shut and secure onto said filter.

Done!
You are now rolling coal.

 

i feel dumber after reading this