Delo 400 Mg

[AH64ID]

When you say CL so you mean CI? CL isn't a specification I have heard of.

The oil formulation change was primarily based on particulate filters, not fuel. If CI oil is used it can plug up the DPF, so a low ash oil had to be formulated. To get ash down some of the ZDDP had to be removed and replaced with a different additive package. Both CI and CJ are designed for up to 500ppm fuel.

CJ oils are fine, but I don't think they are as good as CI oils for non-DPF trucks, this includes deleted 6.7s. The high ZDDP is important for flat tappet motors, like the ISB. The substitute in CJ oil is adequate, and since CI oil not readily available then just run a diesel oil of your choice.

There are plenty of people with a lifetime supply of CI oil in their garage due to changes from CI to CJ.

[diesel4life]

I understand why the formulation was changed, but thats not the question at hand. What I don't understand (and the intent of the original post) is the argument for the higher TBN, along with Calcium, phosphoros, and such. Those additives were all used to counter the higher sulfur fuels, so now that ULSD is the norm, why is cl4 preferred? I have read studies that have confirmed the depletion of ZDDP isn't as big a deal as people make them out to be, especially with the addition of better plating materials in the CJ oils then was previously available.

[AH64ID]

Both CI and CJ are designed for up to 500 ppm fuel, I am not sure there is any basis behind additives changing on CI 15ppm fuel. CJ has to be 500ppm compatible, and that is the max that CI oil was compatible with.

 

ZDDP is a big deal on flat tappet engines, especially if you run a cam and/or heavier valve springs.

 

The CJ oil is adequate for many, but I don't think it's better than CI-4+ and CI-4+ will last longer.

 

Nearly all of the changes to CJ where based on exhaust after treatment, not the sulfur content.

[diesel4life]

It is hard to find good current info on CJ spec oils, but in the earlier days nearly all the oil manufacturers recomended either monitoring with OA or shortening the service intervals when using a CJ oil with 500ppm fuel. That may not be the case anymore, but it doesn't really matter being it is not even available anymore. Again, I understand the reasons for the changes in the specs being due to the dpfs, but some of the higher detergents used in previous spec oils is simply not needed with the cleaner fuel. There is a correlation between fuel types and amounts of oil additives needed for soot dispersion and controlling oil oxidation . As far as the ZDDP, what was the requirement in change from cl4 to cj4, something like .02% reduction?  I see where many companies have switched to molybdenum as an alternative.

Remember there are two tests specific to Cummins engines that oil manufacturers are required to pass to meet CJ4 specs, one specifically for ISB engines for valve train, camshaft, and tappet wear.