What oil for 2020 cummins? - Merged oil threads

[AH64ID]

Amsoil does not make sense for me as my oil ages out wayyy before it meets the mileage requirement. I do notice loss running the T6 usually when I tow hard through hill country. Then I saw the blurb on a 5G FB page about T6 being volatile compared to others (no mention as to what was best) so I guess I’ll do some research and testing.

With my dealer pricing the Amsoil isn’t really that expensive for a full synthetic and I like the properties of a Group IV synthetic vs a Group III.

I wonder if the volatility of Rotella is how it got the Rosmella name??

A quick search shows T6 at 12.8%, which is pretty high. Likely from being a Group III synthetic.

 

[flan]

With my dealer pricing the Amsoil isn’t really that expensive for a full synthetic and I like the properties of a Group IV synthetic vs a Group III.

I wonder if the volatility of Rotella is how it got the Rosmella name??

A quick search shows T6 at 12.8%, which is pretty high. Likely from being a Group III synthetic.

Yea next time I get a minute I’ll gather the 5/40 syn producers and research their properties. I always did notice the rotella stank after an oil change using 15/40 on the older trucks. Remember ram came out with the lemon smell oil additive to combat the complaints?

 

[flan]

 

[AH64ID]

I hadn’t seen that before. Too funny.

Now they just vent the crankcase into the turbo, so you wouldn’t smell it anyways.

 

[Brutal_HO]

Amsoil does not make sense for me as my oil ages out wayyy before it meets the mileage requirement. I do notice loss running the T6 usually when I tow hard through hill country. Then I saw the blurb on a 5G FB page about T6 being volatile compared to others (no mention as to what was best) so I guess I’ll do some research and testing.

IMHO, oil only "ages out" if you're concerned about warranty.

 

[flan]

IMHO, oil only "ages out" if you're concerned about warranty.

True. Filter media would concern me more than oil breaking down.

 

[AH64ID]

IMHO, oil only "ages out" if you're concerned about warranty.

True. Filter media would concern me more than oil breaking down.

Oil does start to break down as soon as the engine is ran, which is where the time comes into play.

I've seen low mileage oils be out of TBN at 12-14 months, so if you want to extend past the OEM time interval (or oil time interval with oils like Amsoil that publish their own time) I would run a UOA to see what the TBN looks like.

 

[tchur1]

Oil does start to break down as soon as the engine is ran, which is where the time comes into play.

I've seen low mileage oils be out of TBN at 12-14 months, so if you want to extend past the OEM time interval (or oil time interval with oils like Amsoil that publish their own time) I would run a UOA to see what the TBN looks like.

A bit off topic but Im feeling lazy and dont want to read the entire thread here. Coming up on an oil change and the Rotella volatility conversation has me considering amsoil instead. Do you use Max Duty or Heavy Duty?

 

[AH64ID]

A bit off topic but Im feeling lazy and dont want to read the entire thread here. Coming up on an oil change and the Rotella volatility conversation has me considering amsoil instead. Do you use Max Duty or Heavy Duty?

I am using the Heavy Duty 5w-40 on my '22.

I ran the SS Max-Duty 15w-40 on my '18 so I could get the Amsoil 12 month interval backing, but I don't see the need for SS on my '22.

 

[tchur1]

I am using the Heavy Duty 5w-40 on my '22.

I ran the SS Max-Duty 15w-40 on my '18 so I could get the Amsoil 12 month interval backing, but I don't see the need for SS on my '22.

Perfect, thank you.

 

[Brutal_HO]

Oil does start to break down as soon as the engine is ran, which is where the time comes into play.

I've seen low mileage oils be out of TBN at 12-14 months, so if you want to extend past the OEM time interval (or oil time interval with oils like Amsoil that publish their own time) I would run a UOA to see what the TBN looks like.

Very true and should go without saying.

 

[AH64ID]

Very true and should go without saying.

It should, but I’ve known plenty of folks who have run oil 2-3 years because the miles were low.

 

[John Jensen]

It should, but I’ve known plenty of folks who have run oil 2-3 years because the miles were low.

You offer good oil info. Causes me to wonder what the TBN was for those folks who ran the same oil for 2-3 years.
Is there any data on oil used that long? I've read where the oil should be changed when the TBN gets to 50% of its original TBN, but I haven't been able to find any actual TBN data for the 2-3 year old oil.

 

[AH64ID]

You offer good oil info. Causes me to wonder what the TBN was for those folks who ran the same oil for 2-3 years.
Is there any data on oil used that long? I've read where the oil should be changed when the TBN gets to 50% of its original TBN, but I haven't been able to find any actual TBN data for the 2-3 year old oil.

I haven't seen any UOA's on oil that old.

Cummins publishes data that states TBN on a UOA should be 2.5 number minimum or half new oil value or equal to total acid number (TAN).

 

[John Jensen]

I haven't seen any UOA's on oil that old.

Cummins publishes data that states TBN on a UOA should be 2.5 number minimum or half new oil value or equal to total acid number (TAN).

Bummer, I was hoping with your knowledge you would have some UOA data.
With no actual data, it's hard to accept that 2-3 old low mileage oil is bad to run. That said, I do accept what the experts say about it..

 

[AH64ID]

Bummer, I was hoping with your knowledge you would have some UOA data.
With no actual data, it's hard to accept that 2-3 old low mileage oil is bad to run. That said, I do accept what the experts say about it..

I have done some 1 year old oil UOA's and some oils are depleted and needed changed and others didn't. I was only able to find one old report from my 03 4Runner but in 12 months and 8,000 miles the TBN was down to 1.4, not good for much more than the 12 months. I recall having tried one other oil and it was even lower after similar use, but that was 15 years ago and can't find that report. That 4Runner has had annual changes, regardless of miles, since we bought it in 2005. It currently has 232K miles on it, probably over 7K hours, and doesn't use any oil. The manual calls for 6 months or 7,500 miles on oil changes.

I ran Amsoil AME in my 05 for 14 months once and the TBN was down to 6.14 from 12.1. Based on Cummins guidelines it was due to be changed by TBN, but the UOA analysis didn't care bout the TBN being 1/2 of new. I did change the oil, but that was based on soot loading.

On the rebuild I never had any issues with soot in the oil and the most miles I did a UOA on was 10,500 and right at 12 months. The TBN was 8.46.

 

[OLEJOE]

Generally speaking the closer the viscosity range the lower the volatility, so a 10w-30 should be less volatile than a 5w-40.

In the series of Amsoil I run the 10w30 is 4.5% and the 5w-40 is 9.2%. I did think about that when selecting 5w-40, but I don’t think it’s an issue. I have almost 11K miles on my oil and the level is at the same place it was when I changed, so unless it’s adding fuel at the same rate it burns off I don’t burn much, if any.

The test is done at 250°C and we don’t operate anywhere near that hot.

That’s interesting. The flash point for the RT6 5-40 is 233*C. Normal temperature should be around 100*C (212*F) and mine hasn’t used any unless it’s being diluted with fuel at the same rate and oxidizing at the same rate to keep viscosity the same. I think that’s a pretty good stretch for that to be happening.
Volatility is measured at 250*C.
That’s 482*F.

 

[Mikerob14]

Alright. I’m gonna be honest. At the start of the thread I was thinking Rotella… and now by the end I’m thinking Amsoil… it does sound like the consensus is 5w-40 even though I wouldn’t be seeing temps below 0. Any opinions between the two that would stand out? I will be putting around 10k a year on it so if that factors in then so be it. Thanks for the insights.

 

[H3LZSN1P3R]

Alright. I’m gonna be honest. At the start of the thread I was thinking Rotella… and now by the end I’m thinking Amsoil… it does sound like the consensus is 5w-40 even though I wouldn’t be seeing temps below 0. Any opinions between the two that would stand out? I will be putting around 10k a year on it so if that factors in then so be it. Thanks for the insights.

The difference is pricing basically. I run amsoil 5w40 as its cheaper than a pail of shell and shipped to my door. I used to run shell before the Rona screwed everything up as it was cheaper

 

[OLEJOE]

Amsoil is cheaper than $23 per gallon ?