New truck

[m.parker]

Does a brand new Cummins diesel have break in oil in it? My company truck has like 4000 miles on it and the oil is black. I wouldn't think the oil would be that dirty already.

 

[Roper46]

I had this same question ref the oil on my first Ram, a 2020 2500. I learned that with the Cummins the oil is always black.

 

[H3LZSN1P3R]

No its not break in oil and its black after the first 100 miles even

 

[Cseybert]

Diesel soot comes with the territory.

 

[Swede 21 2500 Big Horn]

Diesel engines will turn the oil black as a result of the higher compression and a certain amount of compression blow by as a result. The engines do not require a "break-in" period. However some of the drive train components require it.