I've been looking for the MG oil and all I can find is the LE. Does it exist, does it make a difference? It's what's recommend for 24 valve cummins.

Edited February 18, 201411 yr by joecool911

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.

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.

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.