Oil thoughts....please

[JR]

I didn't realize any 5.9 ever had a 15k mile OCI, but my 98 which was probably much easier on oil in terms of fuel dilution, soot load, and shear than any CR engine was rated for a maximum of 7500 mile OCI.

GSBrockman has a few UOA's in the neighborhood of 15,000 miles with good results. Most all towing miles.
I've seen UOAs of both 6.7 and 8.3 running Shell Rimula CJ4 on 500 hour OCI. No a big deal.

 

[JR]

The TBN of CK is lower than CI, meaning all other things equal it won't last as long.

If one is running extended drain intervals this could be an advantage. For standard drain intervals it's just not needed.

 

[AH64ID]

They weren't all 15K miles, just like the new trucks are "up to" 15K miles.

GSBrockman's last change was 14K miles, but only 241 hours. In the OTR/industrial world hours are more important than miles and 241 hours isn't much at all for oil.

Your 98's OCI was developed around CH oil. CH oil did a better job of allowing soot to be filtered by a bypass filter, but that same ability meant that soot was more damaging on motors without bypass filters, hence the lower OCI. CI oil was the first oil that was really good at thinning the soot produced by EGR which is what lead to the increased OCI's in the mid 2000's.

My dad just bought a 2017 Ram and it calls for CJ instead of CK, which surprised me since 2017 was another benchmark on emissions/oils. Maybe CK is just out earlier than required to get it into circulation.

 

[AH64ID]

If one is running extended drain intervals this could be an advantage. For standard drain intervals it's just not needed.

Which is why it dropped with CJ. Who needs TBN when the oil is fuel diluted long before the additive runs out.

I don't need the TBN for OCI miles, but it sure is nice when I just do one oil change a year.

 

[JR]

TBN levels dropped along with the sulfur levels in fuel and it simply wasn't needed in the equation anymore. The early fuel dilution issues certainly weren't intended, and were mostly resolved well before SCR although they were still there to a degree. I don't follow what you feel the advantage of having more tbn is since your running standard intervals? but in your case (and mine) more doesn't necessarily provide more protection. TBN drops linearly as it's consumed. IMO this Kind of falls in the same boat as the argument for synthetics. If running extended intervals or climate dictates they absolutely have their place, otherwise it's hard to justify the significant increase in costs when I've seen so many of these engines do well on cheap fleet spec oil at 500 hr intervals.

We just got a brand new 2017 Grove GRT 8100 with a 6.7 Cummins with SCR after treatment. Surprisingly it also calls out CJ4. Im curious when they will start mandating the new CK4/FA4 spec.

 

[AH64ID]

I think the TBN dropped because it could due to short OEM OCI’s. The OEMs knew that the emissions technology of the time would add lots of fuel to the oil and once the oil companies knew there wasn’t a point in ensuring a long lasting oil when fuel would kill it. If you noticed the TBN is back up in CK oil, which is designed for the same fuel but current emissions equipment is easier on oil and thus more TBN is needed for longer OEM OCI’s. It’s not as high as CI oil, but it’s higher than CJ.

TBN is depleted by time as well as mikes, which is where the 6 month OCI comes into play. Once an engine is started after an oil change the oil starts to deplete the TBN, even if it’s not driven much.

My OCI is 12 months and why I like higher TBN and synthetic. The synthetic also lets me run me oil regardless of ambient temps. Based on my UOA I could run the oil longer but 12 months is plenty for me.

To me the oil changes after CI were made to match fuel changes. Just like 15ppm fuel is “cleaner” it needs additional lubricity modifiers.. CJ oil isn’t as good for flat tappet motors and needs a different additive package to keep them alive. It really makes me wonder how long the ISB will stay a flat tappet motor.

I’m wondering if CJ will be used until Cummins goes to EGRless motors, which is rumored to be only a couple years out.

 

[JR]

There was a direct correlation between lower sulfur fuel and lower tbn in oil, if you recall the short period of time when 500 ppm sulfur was available in offroad fuel OEMs were recommending shortened service intervals when using CJ4 due to lower alkaline reserves.

On my 98 I ran synthetic (Schaeffers) with a bypass filter. Without going back and looking at it, my last UOA was just north of 17k miles, TBN was better than half of what it was when new. Granted there was something like 2 qts of make up oil over the duration but I've always had good results with CJ4 oil. Excellent wear numbers, viscosity retention, more than adequate TBN remaining. All the things you need out of an oil.

 

[jjdiesel]

Good info guys...thanks for your input.

 

[AH64ID]

Not too long ago Cummins stated that TBN needed to stay at 50%, or greater, than new (among other criteria, but 1/2 original was the common limit). The current oil bulletin states no lower than 2.5.

That’s a significant change, and I wonder why.

 

[JR]

Not too long ago Cummins stated that TBN needed to stay at 50%, or greater, than new (among other criteria, but 1/2 original was the common limit). The current oil bulitien states no lower than 2.

That’s a significant change, and I wonder why.

The bulletin I have saved from Quickserve from 2009 says TBN 2.5 minimum OR half of new oil value OR equal to total acid number.

I haven't seen anything since 20086 came out.

 

[AH64ID]

The bulletin I have saved from Quickserve from 2009 says TBN 2.5 minimum OR half of new oil value OR equal to total acid number.

I haven't seen anything since 20086 came out.

Yeah same older one I was looking at. 1/2 of new value is going to be the limiting factor 99.9% of the time.

I found a current listing but it's not a bulletin.

It states for <19L it's 2.5 TBN and for >19L it's 2.5 TBN or equal to TAN.

It can be found here if you have a quickserve account.

https://qsol.cummins.com/qs3/portal/service/manual/en/5411406/

I also found this. I find it interesting the CJ oil is never recommended, only permitted. CI and CK are the recommended oils.

 

[JR]

I also found this. I find it interesting the CJ oil is never recommended, only permitted. CI and CK are the recommended oils.

Probably has to do with the fact that 20086 is the latest standard, and according to their note iswhat they prefer given the use of ULSD

I believe CI4 is still a very common spec in much of the rest of the world (all CES are global standards), but then again so is sulfur levels in fuel in excess of 2,000 ppm. Some countries have very recently adopted lower levels in the 300-500ppm range in an attempt to curb air pollution, but there's still a lot of heavy fuels being burned in old equipment, so it makes sense that an old (to us) specification is still called for on a global level.

 

[JR]

Copy and paste from

https://qsol.cummins.com/qs3/portal/service/manual/en/5411406/

Global fuel quality plays a significant role in selecting the appropriate oil. For locations with fuel sulfur > 15 ppm and not using aftertreatment, do not use oil meeting Cummins® Engineering Standard (CES) 20081, CES 20086, CES 20087, as the starting total base number (TBN) is typically lower and may require reduced oil drain intervals. For fuel sulfur > 15 ppm CES 20078 is recommended.

Also, to back up my previous post,

Note : CES 20086 is recommended for use anywhere CES 20081 was previously recommended. CES 20086 oil can be used in any diesel engines that are running on ULSD fuel.

The link takes you to the same general page as did in Johns post, but the info is in there.

 

[AH64ID]

Nice find!

 

[JR]

Nice find!

LOL, even though your link takes you to a general page it's on the same page as what you screen shot. It's been a while since I've been on Quickserve. They have a lot of good info "straight from the horses mouth". Very valuable resource.

 

[AH64ID]

LOL, even though your link takes you to a general page it's on the same page as what you screen shot. It's been a while since I've been on Quickserve. They have a lot of good info "straight from the horses mouth". Very valuable resource.

Yeah I just found it.

I was in a hurry this morning and missed it.

 

[Freebore]

TBN levels dropped along with the sulfur levels in fuel and it simply wasn't needed in the equation anymore. The early fuel dilution issues certainly weren't intended, and were mostly resolved well before SCR although they were still there to a degree. I don't follow what you feel the advantage of having more tbn is since your running standard intervals? but in your case (and mine) more doesn't necessarily provide more protection. TBN drops linearly as it's consumed. IMO this Kind of falls in the same boat as the argument for synthetics. If running extended intervals or climate dictates they absolutely have their place, otherwise it's hard to justify the significant increase in costs when I've seen so many of these engines do well on cheap fleet spec oil at 500 hr intervals.

We just got a brand new 2017 Grove GRT 8100 with a 6.7 Cummins with SCR after treatment. Surprisingly it also calls out CJ4. Im curious when they will start mandating the new CK4/FA4 spec.

I am not really surprised that 2017 models call for CJ-4 as the first production started before CK-4 was ready and in the pipeline. I would like to see what the 2018 models call for - if they are not specifying CK-4 I would be surprised.

 

[JR]

The way things are going I'll be surprised if we don't see a change in viscosity real soon. The ISX platform has been FF with 10w30 for 4 years now, if it can be done reliably at the HD level with any FE benefits realized I'd be all for it with the ISB.

 

[AH64ID]

The way things are going I'll be surprised if we don't see a change in viscosity real soon. The ISX platform has been FF with 10w30 for 4 years now, if it can be done reliably at the HD level with any FE benefits realized I'd be all for it with the ISB.

The ISB has been allowed to run a 30wt for a long time, as long as it meets a high temp/ high viscosity sheer of 3.5.

I ran one for a while and never had good UOA’s on it, and I don’t think the motor was any more fuel efficient. When I did a cam there was more wear on the tappets than the miles I had. I think it was the 5w-30.

 

[JR]

Cummins might still allow it within a small operating range but 5w40 and 15w40 are the only viscosities called out in my 14 owners manual. That being said, that's a world of difference than an engine being designed to run off of it like the ISX platform.