CJ-4 vs CI-4

[dnewton3]

I have reason to understand that Cummins does in-dept testing. I have a relative that works there, so I have some small amount of insight as an overall understanding. Additionally, I worked at Ford for 16 years. I'm pretty sure that OEMs do thorough testing. Do they occasionally get things wrong? Yes the certainly do. Examples would be sludger engines such as the SL2 and some Toy motors. But as a whole, OEMs get things right far more often than they get things wrong.

That in mind, consider the following:
Cummins and Ram recently announced that the OEM OCI is now 15k miles for the 6.7L engine. Using CJ-4 lube. If these failures are so prominent, then I'd think Cummins would not be advising such a long OCI on CJ-4. I seriously doubt they did that on a willy-nilly whim; I am fairly confident that they put a lot of effort and research into it. After all, several years ago, Cummins was adamantly against extended OCIs. And yet now they reccomend 15k miles? As of yet, there is no governmental agency mandate for OCI durations, so they did it on their own accord, and were not forced to do so.

After all, their warranty risk is what they concern themselves with; they don't pay for OCIs. If there was even a hint of real problems with CJ-4, why would they risk doubling their OCI, when they could just make the owner pay for more frequent OCIs?

 

[Garak]

Originally Posted By: dnewton3
That in mind, consider the following:
Cummins and Ram recently announced that the OEM OCI is now 15k miles for the 6.7L engine. Using CJ-4 lube. If these failures are so prominent, then I'd think Cummins would not be advising such a long OCI on CJ-4.

Another thing to consider was that for about a year or two (recently ended, as far as I know), Dodge was offering lifetime powertrain warranties on Cummins equipped trucks. I can't see that happening if they didn't have confidence in engine and maintenance schedule.

 

[SteveSRT8]

Originally Posted By: Garak
Originally Posted By: dnewton3
That in mind, consider the following:
Cummins and Ram recently announced that the OEM OCI is now 15k miles for the 6.7L engine. Using CJ-4 lube. If these failures are so prominent, then I'd think Cummins would not be advising such a long OCI on CJ-4.

Another thing to consider was that for about a year or two (recently ended, as far as I know), Dodge was offering lifetime powertrain warranties on Cummins equipped trucks. I can't see that happening if they didn't have confidence in engine and maintenance schedule.


Absolutely. Their very survival depends on it! They didn't just pull that spec out of a bodily orifice!

 

[MaxPF]

As it turns out, anyone with a 24V Cummins doesn't have to listen to our back-and-forth and wonder about it. The valve cover gasket is rubber and fully reuseable. You simply remove 5 bolts holding the cover on, remove the cover, and each rocker is held on with a single 10mm bolt. It literally takes 5 minutes to remove the valve cover and pop a couple rocker arms off to inspect for wear. For any 24v owner, that will end the guessing or discussion.

 

[azsynthetic]

Originally Posted By: SteveSRT8
Originally Posted By: Garak
Originally Posted By: dnewton3
That in mind, consider the following:
Cummins and Ram recently announced that the OEM OCI is now 15k miles for the 6.7L engine. Using CJ-4 lube. If these failures are so prominent, then I'd think Cummins would not be advising such a long OCI on CJ-4.

Another thing to consider was that for about a year or two (recently ended, as far as I know), Dodge was offering lifetime powertrain warranties on Cummins equipped trucks. I can't see that happening if they didn't have confidence in engine and maintenance schedule.


Absolutely. Their very survival depends on it! They didn't just pull that spec out of a bodily orifice!


I still remember when Chrysler offered their 7yr/100K power train warranty. They did it to increase sale and not because of any improvement in their power train. They gambled on their warranty policy and lost. If it was not for the government loans there would not be a Chrysler today.

 

[Garak]

Well, the lifetime engine warranty on the Cummins up here was after the bailouts.

 

[dnewton3]

As a belated update, I've got some info to add ...

This past weekend, I did my 400 hour service on my L3430GST, so I took a moment to research this in the manual. Specifically I refer to my 2005(?) model, but I would think this is revelant.


Kubota specifically speaks to using a CG-4 fluid in my manaul, but they preface the comments on fuel used, as we suspected. I did not bring it into work, so I cannot quote it directly, but I can certainly paraphrase ...
Essentially, the spoke of high sulfur fuel and low surphur fuel. ULSD was not even in the market place at that point. They noted that high sulfur fuels were better suited to the use of higher TBN oils (no suprise there, eh?). They also noted that the use of other lubes would shorter the interval (again - no suprise). They specifically wrote that lubes with TBN > 10 were to be used if high sulfur fuels are present. In reality, that's not that high of a starting TBN.


What is clear to me are a few things:
1) Kubota knows that fuel affects oils, if the sulfur is high; that in turn can affect OCI. We BITOGers already are aware of this.
2) Kubota does not "disallow" other lubes; they just don't recommend because they are not motivated to test other lubes. Kubota has no idea of what fuel you use; the choice of fuel and lube is on you.
3) With ULSD now being predominant in US and Canada(?), even off road, there is no "need" for ultra-high TBN lubes, so CJ-4 lubes will do a great job. I've seen some LSD fuels still, but it's rare. ULSD is essentially everywhere now to the (almost assured) exclusion of High and Low sulfur fuels.

You can use CJ-4 with confidence that is it fine in your Kubie; you may have to tailor your OCI if you use other than ULSD fuel. A used oil analysis can certainly help with this decision to set your OCI point.

 

[Garak]

Originally Posted By: dnewton3
3) With ULSD now being predominant in US and Canada(?), even off road, there is no "need" for ultra-high TBN lubes, so CJ-4 lubes will do a great job.

Yep, ULSD up here, too, even for off road applications. As far as TBNs of 10 or greater, it's not very hard to find HDEOs that meet that figure, even in CJ-4. The new Delvac LE 5w30 exceeds that, as does Delvac 1 ESP 5w-40.

 

[miniac007]

Here in europe, all CI-4/CJ-4 HDEO are around 10. For specific usage, we can find some with TBN of 15, but classified in E4 and CF.

Anyway, that's nice to avoid ultra high TBN as it works against anti-wear additives...

I spoke with a ship engineer friend in Madagascar who used ultra high sufur diesel on fishing boats, and oil with TBN around 60 ... It was very bad for engine wear...

 

[Garak]

Originally Posted By: miniac007
Here in europe, all CI-4/CJ-4 HDEO are around 10. For specific usage, we can find some with TBN of 15, but classified in E4 and CF.

60 is a little high.

It's getting harder to find any these days here in the neighbourhood of 14 or 15, but they do exist. The ones that have a TBN in excess of 10 usually have the ACEA specification to go with it.

 

[Nikos_jd]

The Shell Rimula R4L 15w40 Rimula R4L for Europe and Rotella Rotella T 15w40 API specification : CJ-4, CI-4+, CI-4, CH-4, CG-4, CF-4, CF.
oversubscribe and previous specifications.