Mobil Delvac 1300 Super 15W40 CK4/SN
I would appreciate feedback and comments on the current API licensed CK4/SN formulation of Mobil Delvac 1300 Super 15W40. I understand that Delvac is still the factory fill for the L5P Duramax diesel. I just had my first free dealer oil change in my 2017 Duramax.
The past CJ4 formulation of Mobil Delvac 1300 Super 15W40 has performed well in the Dmax based upon user comments/feedback posted both here and on BITOG. I have used the CJ4 formulation of Delvac 1300 Super 15W40 with good results in my 04 Duramax.
Fast forward to today, and the current formulation of Mobil Delvac 1300 Super 15W40 CK4/SN is a universal, mixed fleet heavy duty engine oil. The current formulation has reduced phosphorus levels (800 PPM) making it suitable for use in gasoline engines (SN designation) as well as diesel engines (CK4 designation). Mobil is claiming a 20% wear protection improvement over the previous CJ4 formulation and 50% more wear protection than required in API CK4 engine tests. This is all well and good; however, it would be good to hear comments from Dmax owners who have experience using the current formulation of Mobil Delvac 1300 Super 15W40 CK4/SN.
2017 L5P 3500HD
Last edited by OkDually; 03-31-2019 at 06:27 PM.