Chevron still makes Delo 400 15W40 API CI-4+. However, it is only available in bulk, drums, and 5 gallon pails. If anyone in the SF Bay area wishes to purchase please feel free to contact me. I work for a Signature Chevron Distributor and will be happy to help you out.
The CJ-4 API specification is backward compatible for all previous specifications. The Chevron Delo 400 15W40 LE is CJ-4. It is available in all of the above package styles and also in the 3/1gallon package. I can help with these, also. And, if you need to have the absolute lowest price on the 3/1gallon I would suggest that you hunt the big box stores. In many cases you will be able to purchase them below my cost. This causes many distributors much anguish with Chevron and when we ask the question we are told "When you buy 20 million gallons in one gallon bottles at a time we will be happy to extend the same price to you". Read into that what you will. I have not one bit of doubt that if any of us were to buy 200 Dodges at a time we would also receive better pricing.
The CI-4 will sunset in the future as all previous API specs have and we will be left with only CJ-4. I still currently use the CI-4+ because it is convenient to me and will have no problem using CJ-4 when I am left with no other option. There are newer API specifications on the way. These are all driven by emission requirements primarily. Don't sweat this.
When I asked the question at a recent training seminar at the Southwest Research Institute "OK, so you have taken some of the AW (Anti-wear) and antioxidant package out of the CI-4 oil to meet the lower ash requirements of CJ-4. What have you replaced it with?" I was told that it was proprietary information. And, if I was told what it was that I would have to be... You know the line. Simply put, they have been replaced with other additives. The CJ-4 spec is more robust in all of the parameters that diesel engine oils are tested for and causes me no concern about using it in my truck or recommending it to customers who have mixed fleets that have more CJ-4 requirement vehicles than CI-4 and do not wish to have both oils in stock.
To the best of my knowledge, and I am sure that other knowledgable people will chime in, Chevron is the only one that is still making their Premium diesel engine oil in both API specifications. It will go away at some point and you will be left with only one choice.
CJ-4 was developed because of Emissions requirements. Primarily, lower sulphated ash. This was a requirement for the Diesel Particulate Filter, Catalytic Converter, NoX Scrubber, etc. . The higher SA of the CI-4 oils would cause the filters to become restricted sooner requiring service more often. Secondly, the higher heat loading on the new engines due to retarded timing, increased EGR, multiple injection events for added power and regeneration cycles, tighter engine cowling, and on and on. This required an oil with greater oxidation stability. Total base number in many cases was reduced because the need for it was less due to ULSD and the additive for it would add to the SA number. It is hard to cover this subject in this format, but let me just say this. There will be no negative effect from using CJ-4 in any engine that Specs CI-4 or CI-4+. Except for the slightly higher cost per gallon on your wallet and you have already stated that cost was no barrier.
I hope that this helps.
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