Kubota Interim Tier IV Motor Oils

[5030]

Soot (dark oil) is usually the result of engine blowby. Interestingly, neither of my M9's really darken the oil between changes. Neither does my car.

 

[5030]

Soot is not only a poison, it is abrasive.

Certainly is, just ask Detroit Diesel about the effects of hard carbon deposits in their intake runners.