Co-op DMO 10w30 24k km; 2017 Cummins 6.7

[BrianF]

172,000km on truck, 24,000km on oil. Truck deleted since 100,000km.

This run was, as the title says, Co-op DMO semi synthetic 10w30 CK4. I don't have much of a breakdown, but plenty of towing and the usual frigid cold starts. In fact the last 300+ km were running in -30c with plenty of cold starts.

While iron is trending down, it's quite a slow depreciation. Its still high but I see nothing to suggest the bearings were taking a beating. The oil is oiling.

I see oxidation is up compared to the previously used PeteoCan Duron. Is it a significant amount? It's not flagged albeit I am not well versed in that.

Could the oxidation help retain the viscosity? Probably but I bought a 30 weight and got a 30 weight. Pretty happy with the shear numbers. Co-op states 12cSt as starting viscosity under typical properties.

Now, what I was really interested in, soot. So, fresher engine, full emissions and get .59% soot. Full delete and down to .44%.

 

[fantastic]

Semi-Synthetic possibly has better base oil. Other reason could be oxidized sooner. Would need to do a baseline VOA to determine starting point. Trend looks good & Fe is still high but its going down. Have you considered a 0w-40 or 5w-40? Thanks for sharing your Cummins UOA.

 

[BrianF]

I contemplated sending a VOA but ended up using up my stock. I have some for the farm, albeit a year newer but I just may send in a sample. I have an extra sample kit......

I have thought about 40 weights and might do a run just to see. Currently in my truck is a clean out of the oil shelf: 8L 10w30, 3ish of 5w40 and an oil filter worth of 0w40.

Years and years ago, I got into reading @dnewton3 's posts on running 10w30 in the Duramax. It gave good protection, a good semi synthetic has similar cold flow to 5w40, it's less expensive and less shear prone.

 

[fantastic]

Years and years ago, I got into reading @dnewton3 's posts on running 10w30 in the Duramax. It gave good protection, a good semi synthetic has similar cold flow to 5w40, it's less expensive and less shear prone.

Common for folks to recommend a 10w-30 over a 5w-40 b/c of what you mentioned but everyone of mine and a few others that actually tested 40 grades in our trucks managed to maintain a higher viscosity throughout the interval. I don't see any benefit to starting with a lower viscosity simply b/c it shears less. The starting & ending viscosity is what matters & 40 grades have proven they perform better. Today's CK-4 oils are more sheer stable than ever before as well. I do understand the cost reasoning however.

 

[56Cummins]

I have thought about 40 weights and might do a run just to see.

Do it.

I erased my post yesterday saying the same thing. I always want to see a different grade tested. If you had 20w50 in it, I would wonder the difference 15w40 would make.

Thanks for posting the report.

 

[BrianF]

I had looked at another truck owners UOA. He runs a newer Ram 5500 commercially hauling albeit towards the southern states and he is north of 200,000 miles. He normally runs T6 5w40. His iron was trending about 1ppm/1000miles. He also ran an index of T5 10w30 (if I recall), his iron went up to about 1.17ppm.