MC 15w-40 has been a CJ-4 oil for quiet a while now...

SAE 15W-40 Super Duty Diesel Motor Oil

With a TBN of 8.4...
http://www.fcsdchemicalsandlubricant...per%20Duty.pdf

Honestly, IMHO, I would not get too worked up over the CI vs CJ-4 stuff. Yes TBN has dropped from the older to newer spec but most of the acidity in a diesel's crankcase came from blow by and the sulfur in the fuel and exhaust...well with ULSD and sulfur levels dropping from 500ppm to 15ppm (a drop of a mere 97%)...the TBN advantage of CI-4 is totally moot.

Now there has been a drop in Zinc and phosphorus, two long time fan favorite anti-wear additives but most oil companies have increased the use of other anti-wear additives like boron, molybdenum and in some cases titanium. Also CJ-4 oils are designed to handle far more advanced EGR than CI-4 oils and thus handle soot better, which also helps control wear.

I am not saying CJ-4s are perfect by any means, I am just saying they are even as close to as bad as many people claim they are.

Good site for motor oil talk...

Bob Is The Oil Guy - Forums powered by UBB.threads™

CJ-4 is better by any objective measurement. There will always be crackpots resistant to change and new technology. The "CI is better" myth is just another in the never-ending long string of old wive's tales. :c:

That is true however there is still some CI-4 available, and I bought some a few weeks ago AT WALMART. It has a starting TBN of 14 and more Zn and P.
CJ-4 spec puts a limit on Zinc and Phosphorus, two additives which protect your engine from wear and higher levels were eliminated due to pressure from EPA.
Calcium and Magnesium are what control acid caused from soot deposits, and CJ-4 has a lower TBN oil due to a MANDATE that it is to be compatible with modern emissions controls.
You make a point about ULSD that has some truth, but that is not why they had to reduce levels of additive. A simple switch in fuel does not mean you must downgrade your oil.
Not saying CJ-4 is a down grade.. this is not a debate about CI-4 vs CJ-4 in general.
Pressure from EPA and manufacturers to force compliance with new EGR technologies is what made the change happen.
CJ-4 simply limits additives, the real debate has to do with the oil those additives are added to since there were some changes in base stocks.


The acidity is mostly from soot.. and with 307k miles on my truck I prefer a starting TBN greater than 10. My truck does have some blow-by, but it still runs like a top and makes excellent power.



Less additive does not make an oil BETTER. Again, not a debate between CI-4 and CJ-4.
Manufacturers changed the base oil from group II to group II+ and in some cases group II+ with added group III. II+ is simply a highly processed group II, the group II we've been using for years. If you've bought oil in the last 10 years that was petroleum derived you were running group II. The last few years most every oil on the shelf has been formulated using group II+, an improvement in the base oil that better protects from wear and is more sheer stable.
THE TRUTH is this improved base stock is a large part of the reason for CJ-4 oils looking "good", after-all your base oil is the foundation of your motor oil.
There is no hocus pocus in motor oil, everything is laid out in a scientific method, just read the data.
I'm know you would agree a new group II+/group III oil formulated at CI-4 levels would be an AWESOME oil. Well, my point is there were CI-4 oils which used improved basestocks before the switch to CJ-4. The only thing that *changed* was a slight reduction of TBN additives and anti-wear additives as dictated by API.


BITOG (bob is the oil guy) is a great site, I've been on there for 12 years.
I've also discussed the details of motor oil with people in the industry, in person, for hours, just to verify my own understanding. The internet is good, but good ol face to face can be better. I've never formally studied tribology but a tribologist who knows more than I ever will told me that my understanding is correct and spot on.
This was after I spent hundreds of hours studying oil and the different characteristics that make up a good engine oil and a great engine oil. I have a decent understanding of why one is better than the other, but often times people argue because they are brand loyal and want to continue using what they've used for years.
It's like watching a bunch of teenagers argue Ford vs Chevy.
Well, I've owned them all.
Loyalty is important to me, too, but to be honest I want the best oil for my engine and I will not settle for something less. Of course it is all relative, I want the best oil at what I see as a "reasonable price".

For me, it is Mystik JT-8 15w40 / 15w50 for summer use.

Look, I'll level with you guys.
We are all in this to help each other and learn, at least that I why I am here.
I will share everything I know with you in order to help the best I can, because when I need help I will be the first to ask when I realize it's something that requires attention to detail. I'm looking to do some fine tuning to my pump and I will probably consult someone who has more experience fine tuning to get minimal smoke and maximum torque. I've got a new #10 fuel plate to install before I make any more adjustments.

I've said my piece in this discussion.
Mystik JT-8 synthetic blend takes the cake, 25-30 dollars for 2 gallon containers.
You have your pick of 15w40 or 15w50.
Enjoy and y'all take care.

I have not seen a CI-4 at a consumer since about 2007. Yeah but most advances in motor oil, including CI-4 has been cause of industry (EPA usually) standards changing. Also it is not like Phos and Zinc are the only two players in the anti-wear game...borron, moly and (at least conco-phillips...or whoever they will be once they are done breaking up) titanium has been added to the newer oil to aid in reducing wear.

In my mind at least blowby does not just refer to the pressure induced into a crankcase by combustion but the by products as well. I like a TBN around 10 as well, most of the oil I can get at wally word (delo, delvac, rotella...all have a TBN around 10 (delo being the slacker of the group at 9.6 :tu:. Which is more than enough for my 5-6.5k OCIs.

Like I said before with a drop in Phos and Zinc, many manufacturer's moved to other additives so at least to me I don't see a drop in additives over all. Yeah is added this and that great but the oil doesn't fit the application or service requirements then it doesn't make any sense. For example, added anti-wear additives ain't worth diddly if your running 5-7.5k assuming reasonable operating environment cause your dumping the oil long before the additives or TBN has been consumed. At least based on what I have seen on UOAs, your wallet cares more about what oil your running than your engine...but of course that is just my opinion.

Take it easy:c:

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Geez guys...we are talking motor oil....it is not like we are talking about something important like beer.:c:

You're absolutely right on, it has been just about extinct for years.
I thought I got lucky and found something rare, that was my error.
Upon closer inspection you can see the letters are so close together when I turned the bottle over to read it I saw it as CI-4. It's also marked CI-4 Plus, but of course the top designation over-rides it. Wishful thinking on my part!!
What's funny is I looked at the API label only and CJ-4 is also specified below but all I look at is the API label.
https://www.dieselbombers.com/attach...1&d=1327732224

Right again on the additives, though Zinc and Phosphorus are most prevalent.
And as you probably know Rotella has absolutely 0 Moly.




I will take the extra additive if I can get it. If you don't want your onion rings, I'll take them :yeah:
I too do-not run my oil to the point that it's barely adequate.
Bingo on the wallet, I want the best bang for the buck, which is why I like JT-8.
A synthetic blend for the same money, and it's available in 15w50 diesel formulation!
You might take a serious look at it, in fact I might have it analyzed just so I can get people running a semi-synthetic for the same money.
Analysis would be worth it. From what I've seen in the past they DO-NOT skimp on additives. Prior to CJ-4, Mystik JT-8 had a very robust additive package.

Have you ever taken a look at JT-8?
What do you run now?

If I can convert some people it will have been worth the effort :yessir:
Would be too bad if it went off the market because not enough people were buying it.


You're lucky I'm not a preacher preachin' the good word.. :scare2:


Cheers :c:

Yeah Rotella, like valvoline and formual shell gasser oil, doesn't have the greatest looking spec sheet or VOA but the UOA always seem to come back fine.

You can have em, they give me gas. :scare2:

Right now I got Rotella T5 10w30 in my 7.3, seems to be doing well. Helps with the cold starts, honestly I have heard of Mystik but I have not ran it (at this point is has to be one of the few oils I haven't ran yet). I don't think I would run the 15w-50 just cause at operating temp it might be a little thick for the HPOP, but if I can find the 15w40 lying around I might try to give it a whirl.

Take it easy good sir.:c:

Where do u get the Jt-8 at?

Looks like tractor supply carries it.

Mystik Lubricants

Tractor, O'reilly, Advance, Autozone, ect

Mystik is a Citgo subsidiary/product. They are in bed with that Venezuelan dictator, supplying free heating oil for the slave labor down there.

Money spent on Mystik/Citgo products supports a brutal South American dicatorship. There's lots of other good or better lubricants out there with U.S. interests behind them.