The Cummins only requires good, clean fuel. Additives are not necessary. Sometimes we are bad about this syndrome; "if a little is good"... . I am not saying this relates, just sayin... ...
Nick
I ran 2 tankfulls of additive in my '07, when I had about 20,000 miles... it did NOT like it. One night I was stranded for over a half hour in a restaraunt parking lot, felt like she was running on 2 cylinders and couldn't hold 2nd gear before stalling. Since then I have stayed away from all of the cetane boosters and additives.