YouTube UOA Testing of Amsoil SS vs Penzoil Ultra Platinum on Ram 2500 w/6.4L HEMI

[Pablo]

I did not know that Cu catalyzes oxidation. Being Amsoil SS is very oxidation resistant I'd say it's not of concern.

View attachment 292977

Do you know the virgin oxidation number of the SS 0W-40?

 

[edhackett]

I did not know that Cu catalyzes oxidation. Being Amsoil SS is very oxidation resistant I'd say it's not of concern.

I had trouble finding an appropriate article that was not behind a pay wall. This one turned out to be relevant. What was really interesting was the finding that the relative concentration of antioxidant decreased with increasing temperature. At 300C no antioxidant was found. This could be an important factor in Hohn's findings and the fact that we see otherwise clean engines with fully stuck rings.

Effect of iron and copper on the thermal oxidation stability of synthetic hydrocarbon aviation lubricating oil​

The objectives of this study are to (1) characterize properties of lubricating oil using advanced polymer chromatography (APC), gas chromatography/mass spectrometry (GC/MS), pressure differential scanning calorimetry (PDSC); (2) investigate the effect of Cu and Fe on thermocatalytic oxidation of lubricating oil under different temperatures (200, 230, 250 and 300 °C; (3) determine the molecular mechanism of lubricating oil and Cu/Fe under high-temperature. This study highlights the mechanism of thermocatalytic oxidation of aviation lubricating oil at high temperature in the presence of metal catalysts.

Ed

 

[Hohn]

@dnewton3
Since I have a background in stats, I can appreciate all the x-bar R and SPC stuff and confidence intervals and Z testing and such. I've done the R90C90 work and can sort of intuit that stuff now. I've analyzed data from MATLAB to JMP to MINITAB to EXCEL and back-- everything from reliability/warranty data to engine test cell data to field test data. I'm talking data files where the farthest column is XIV and tens of thousands of rows.

And I'll back you up-- if you want to publish a paper in a lubrication journal declaring one oil better than another, you need a massive sample size and a good gauge R&R study to accompany the lab data. NIST traceability, calibration certs, all that.

But I think you're missing the mark in insisting that you can't learn *anything* to distinguish oils short of such a scientific study. You don't just magically transition from "completely inconclusive" to "Nobel committee called me" on a step function basis. There is a spectrum. And there is useful information to be gleaned. If I shot a rifle one time and hit a 12" target at 100y, how accurate/precise is that rifle? I can't say with certainty. But I know there's a good probability I can hit a 12" target with hit because my first shot did just that, and-- almost tautologically so-- the first shot represents the most likely outcome. So my confidence in hitting it a second time is much higher than if I'd never shot it at all-- because it's already done so once. So with a sample size of two, I've gleaned useful but anecdotal information.

If I move a light switch up and down, the light goes from off to on and it doesn't take very long to become convinced that moving the the switch causes the light to change and that moving it one direction vs the other always causes the light to move the same direction.

Now what if instead of the light going off and on it just got the tiniest bit dimmer or brighter? Twice in a row it got brighter when you moved it up and got dimmer when you moved it down. When do you conclude that one position of the switch is brighter than the other? Do you need a NIST-traceable light meter with precise quantification of luminous flux? Or can you trust your eyeballs enough to have a reasonable confidence that one position is brighter than the other?


So what are reasonable statement that can be made about the UOA shown in the OP?
-- The change in aluminum levels is nonexistent and essentially zero. There' no difference between these oils.
-- There's no discernible effect on iron levels. Changing back to PUP had no effect on iron vs SS iron levels. There's no difference between these oils.
-- The copper difference is *absolutely* discernible and real. Two runs of SS trended copper much higher and kept going, only for the PUP to revert to the same prior copper level, which was half of the SS value.

What's misleading in the UOA report is labeling copper a "wear metal" when it's very likely to be leaching vs wearing. Copper is catalytic and quite reactive. And how exactly does one "wear" copper into the oil without also wearing any aluminum, tin, zinc, or iron?

To my knowledge, pure copper does not exist in most oil-wetted surfaces in a modern engine. It only exists as a brass or bronze alloy. I know that's true of Cummins engines at least because our engineering standards forbid pure copper on oil wetted (and fuel wetted) surfaces. The injector combustion seals are one of the only places you'll see pure copper on a Cummins engine.

Which means any wear particle generated that contain copper will also contain the other alloying elements-- tin or zinc especially, but perhaps even lead.

The only way copper can spike up without taking any other element with it is if it is, in fact, leaching and not wear.


So at the end of the day, I interpret this UOA as saying there's no discernible wear performance difference between the oils, and that the high ester content of the Amsoil is leaching copper from a bushing alloy somewhere (presumably valvetrain), and this will come back down after the surface depletion and a bit of passivation.

If a third run of SS showed the copper staying higher at 10ppm/1k miles, I'd abandon SS for this engine because chronic high copper levels are an accelerant of piston deposits. And since Amsoil's stout ester dose is presumably rooted in cleanliness desires, that would be counterproductive.


Based on copper alone, I'd say this is a "win" for the PUP and there's no need to pull 30 samples to reasonably conclude that. The copper went up and the SS went in and it came back down when the SS came out. Cause and effect.

There's no way to translate these results into engine life or failure probability. But that's not the point. The point is upvote vs downvote. To me, the copper leaching of Amsoil gets the downvote here and I'd recommend the PUP here confidently and not need 30 samples to have that confidence.

I was misreading the report (left to right vs right to left) and didn’t realize the copper level of the 2nd Amsoil was already dropping. I think that with the correct understanding that the copper was already dropping so much, it’s eliminates the last possible distinction between these oils.

THere’s no difference between these oils in terms of wear at this OCI. And given no difference, I’d still give the win to PUP based on 1) cost, and 2) achieving it with a milder add pack.

However, I’m quite confident that if the OCIs were 10k ore more, in the long run the AMSOIL would outperform in cleanliness and the overall engine durability would be better. I’ve argued before that cleanliness in the long run is more important than a couple ppm wear difference. And this stout ester kick of SS here all but assures that if OCIs were longer, the Amsoil would run much cleaner and give the best chance of long run durability.

In the end, it seems to me you could either run PUP at 5k OCI or SS at 10k OCIs and have the engine be about equally durable, equally clean, and probably cost about the same.

 

[buster]

Do you know the virgin oxidation number of the SS 0W-40?

It was 62 but I've seen it fall to around 50 last few UOAs.

 

[buster]

I was misreading the report (left to right vs right to left) and didn’t realize the copper level of the 2nd Amsoil was already dropping. I think that with the correct understanding that the copper was already dropping so much, it’s eliminates the last possible distinction between these oils.

THere’s no difference between these oils in terms of wear at this OCI. And given no difference, I’d still give the win to PUP based on 1) cost, and 2) achieving it with a milder add pack.

However, I’m quite confident that if the OCIs were 10k ore more, in the long run the AMSOIL would outperform in cleanliness and the overall engine durability would be better. I’ve argued before that cleanliness in the long run is more important than a couple ppm wear difference. And this stout ester kick of SS here all but assures that if OCIs were longer, the Amsoil would run much cleaner and give the best chance of long run durability.

In the end, it seems to me you could either run PUP at 5k OCI or SS at 10k OCIs and have the engine be about equally durable, equally clean, and probably cost about the same.

I agree. If you look at all of the ultra-premium oils (HPL, RL, Amsoil SS, Torco, RP HPS) they all use an ester cobase oil. PUP does not contain significant ester. Would be fine for moderate intervals but I think over extended drain intervals SS would keep engine cleaner.

 

[buster]

I had trouble finding an appropriate article that was not behind a pay wall. This one turned out to be relevant. What was really interesting was the finding that the relative concentration of antioxidant decreased with increasing temperature. At 300C no antioxidant was found. This could be an important factor in Hohn's findings and the fact that we see otherwise clean engines with fully stuck rings.

Effect of iron and copper on the thermal oxidation stability of synthetic hydrocarbon aviation lubricating oil​

Ed

I think the ring issue some see as the vehicle ages is due to lack of solvency and detergents. Esters do help with preventing deposits from forming as do detergents/dispersants.

 

[Pablo]

I agree. If you look at all of the ultra-premium oils (HPL, RL, Amsoil SS, Torco, RP HPS) they all use an ester cobase oil. PUP does not contain significant ester. Would be fine for moderate intervals but I think over extended drain intervals SS would keep engine cleaner.

What were some of the Redline Cu PPM back in the day, when someone had a Cu piped oil cooler? It was 100ppm+ as I recall.

 

[buster]

What were some of the Redline Cu PPM back in the day, when someone had a Cu piped oil cooler? It was 100ppm+ as I recall.

RL always reacted with Cu and Pb (bearings) in some engines and per RL it was not an issue.

 

[buster]

Here is a series of UOA's of M1, HPL and RL in a Hemi. Notice the Cu levels.

 

[TiGeo]

Here is a series of UOA's of M1, HPL and RL in a Hemi. Notice the Cu levels.

View attachment 293049

Converting to ppm Cu/1K miles. So in order right to left or oldest to newest:

7.9, 12.9, 4.5, 5.0, 4.7, 4.1, 7.0, 3.9

A different oil used each change which muddies this a bit. Fairly consistent numbers. Higher than I see in my VWs (Cu always v. low) but seems to be normal on these engines?

 

[rstcso]

Here is a series of UOA's of M1, HPL and RL in a Hemi. Notice the Cu levels.

View attachment 293049

The math on the COPPER (1k miles) on the last two samples doesn't add up, so to speak, at least by my iPhone calculator.

Also, why does it say Units in KM, then have rows for Fe and Cu showing "(1k miles)"?

@TiGeo beat me to it.

 

[TiGeo]

The math on the COPPER (1k miles) on the last two samples doesn't add up, so to speak, at least by my iPhone calculator.

Also, why does it say Units in KM, then have rows for Fe and Cu showing "(1k miles)"?

@TiGeo beat me to it.

I didn't even notice there was a /1K miles row for each...whoops.

 

[Pablo]

So what does this boil down to?

Ester ain’t everything

 

[rstcso]

Aside from there being multiple types of oil used , this set of UOA samples shows a couple of things:

• Consistent testing over time helps show what may be considered "normal" for your engine and how you use it
• Check column values closely when you receive the report. Don't assume they are correct. More than once my samples, UOA and VOA, had errors using two different labs. One went back and corrected the values after sending them an email. The other did not/would not correct the report, even after speaking to them on the phone.

 

[JAG]

I do put iron and copper pieces in some of my oil oxidation tests, because of their known catalytic effect on oil oxidation. Amsoil SS caused much more copper leaching on virgin copper than Quaker State synthetic and VRP than at high temperatures. After the copper in the Amsoil SS formed enough of a protective chemical film, the rate of copper leaching greatly decreased.

 

[buster]

So what does this boil down to?

That you need to test your oil against tests designed to promote deposits like the IIIH or TEOST or GM Turbo. That's the only way (expensive) to really know.

I wish more companies showed test data like this but only Amsoil does.

 

[hemioiler]

The math on the COPPER (1k miles) on the last two samples doesn't add up, so to speak, at least by my iPhone calculator.

Also, why does it say Units in KM, then have rows for Fe and Cu showing "(1k miles)"?

@TiGeo beat me to it.

That is my collection of 8 samples in my truck. I live in Canada so distance is in KMs. But I converted ppm/1000 miles because everyone here and on forums seems to work with those units for easy comparison.

Edit: double checked the math, thanks guys for spotting that, had a conversion error to miles but should be fixed in this image below.


Below is updated version, it has another run of HPL. Copper continues to drop as expected.

 

[Pablo]

That is my collection of 8 samples in my truck. I live in Canada so distance is in KMs. But I converted ppm/1000 miles because everyone here and on forums seems to work with those units for easy comparison.

Edit: double checked the math, thanks guys for spotting that, had a conversion error to miles but should be fixed in this image below.


Below is updated version, it has another run of HPL. Copper continues to drop as expected.

View attachment 293116

That is what I would expect and back to where we started this copper discussion

 

[hemioiler]

That is what I would expect and back to where we started this copper discussion

There are many reports on ram forums with guys mainly running Redline and they all show the same trend when switching over in a hemi: a huge initial spike, and then subsequent runs it drops back down.

I'm not worried about it in the slightest.

 

[buster]

There are many reports on ram forums with guys mainly running Redline and they all show the same trend when switching over in a hemi: a huge initial spike, and then subsequent runs it drops back down.

I'm not worried about it in the slightest.

Thanks, I couldn't remember if Cu drops over time but now I do recall that RL in the HEMI shows a Cu spike then slowly comes down.

Your UOA series looks good. Pretty consistent results.