C1 vs C3 lubricants, the OM646LA Engine Wear Test

[OVERKILL]

Thanks @Shannow for sharing this with me!

Presentation can be found here:

https://cectests.org/assets/presentations_publications/cec09_1993.pdf

The reference oils are interesting:

Development partners that we would recognize were:
- Oronite
- Lubrizol
- SWRI
- Shell
- BP
- Infineum

Both reference oils are ACEA approved. SA in the C3 oil is considerably higher (0.75%) than in the C1 oil (0.50%). I expect the C1 oil has API levels of phosphorous, while we know some of the C3 oils, like M1 X3 0W-40, have basically the same level of phosphorous as a full-SAPS oil (900ppm vs 930ppm for FS 0W-40). The impact this has on both the older and the current test results is significant.

 

[BMWTurboDzl]

Being that these are diesel engine tests from 2009 I wonder how C3/C1 would fare today?

 

[OVERKILL]

Being that these are diesel engine tests from 2009 I wonder how C3/C1 would fare today?

Note that the OM646 test is still "current":

But yes, I agree, would be interesting to see the results of that same test performed on current versions of those oils.

 

[56Cummins]

Thats neat, thanks for posting it.

 

[SubieRubyRoo]

Thanks O/K… lends even more weight to my thread/question about how poor the API “standards” are, and shoots down the ludicrous claim I was trolling.

These are Euro tests, with higher levels of protective compounds, and results show extremely poor piston cleanliness. What exactly do people think an API oil subjected to OM646 would show?

To me, valvetrain varnishing is a leading indicator that the oil rings are going to be packed full of CRAP and oil usage is soon to skyrocket…

 

[buster]

Thanks for sharing.

 

[Jetronic]

I've mentioned this before, When we went from A3/B4 oils to C3 oils, I noticed an immediate and impressive reduction in engine cleanliness. The engines didn't blow up, so who cares, right?

I've stayed away from C3 when I could, for my own cars.

Note also that besides the additive levels, the viscosity is also different in the above tests, which can have an impact on wear aswell, and specifically on the rate of additive utilisation

 

[weasley]

Note that the OM646 test is still "current":

No it isn't. You posted the ACEA 2016 sequence, which did use the OM646LA for diesel engine wear testing, but the current ACEA sequence is the 2021 edition which no longer uses the OM646LA.

 

[OVERKILL]

No it isn't. You posted the ACEA 2016 sequence, which did use the OM646LA for diesel engine wear testing, but the current ACEA sequence is the 2021 edition which no longer uses the OM646LA.

I put "current" in quotes, because the test was used long after 2009, the date on the paper. Unfortunately, Afton stopped publishing the Handbook after 2019 (thats what those shots are from) so I'm not sure if Mercedes continued to use the OM646 sequences after 2017.1 or not (the last version in that handbook).

 

[Gentleman farmer]

No it isn't. You posted the ACEA 2016 sequence, which did use the OM646LA for diesel engine wear testing, but the current ACEA sequence is the 2021 edition which no longer uses the OM646LA.

And reintroduced in the 2023 edition .

 

[OVERKILL]

And reintroduced in the 2023 edition .

Whoa, plot twist!

 

[Gentleman farmer]

Whoa, plot twist!

Acea c7 anyone?

 

[weasley]

And reintroduced in the 2023 edition .

So it is!

 

[gogydm]

Could someone please summarize the the results for the less educated of us on here to help with understanding?

 

[Bailes1992]

I've mentioned this before, When we went from A3/B4 oils to C3 oils, I noticed an immediate and impressive reduction in engine cleanliness. The engines didn't blow up, so who cares, right?

I've stayed away from C3 when I could, for my own cars.

Note also that besides the additive levels, the viscosity is also different in the above tests, which can have an impact on wear aswell, and specifically on the rate of additive utilisation

Also, around the time that these ACEA 'C' oils were starting to get used, manufacturers were extending OCI's. As you're aware, most manufacturers here on this side of the pond push 18-20k OCI's.

Shame this test didn't include an A3/B4 'control' or comparison.

Could someone please summarize the the results for the less educated of us on here to help with understanding?

The thinner oil with the lower SAPS (C1) had significantly more wear and deposits than the thicker 'mid SAPS' oil (C3).

 

[Mitch51]

Hi! What about low reference oil and high reference oil respective NOACK?

I recall ACEA C1 was made to be an ILSAC GF-5 sibling, request from some Japanese and American automakers.

I don't know nowadays, but some years ago, Acea C1 allowed 15% NOACK whereas all other ACEA categories allowed only 13% NOACK.
This allowed C1 oils to be particularly crappy and made with very low tier base oils, in regard of C2 and C3 categories.

Usually, NOACK reduces as base oil thickens.

Furthermore, usual C3 oils NOACK have NOACKs between 9% and 11%.

This enormous gap between repective NOACKs make a huge difference in quality between the two reference oils, making this study a bit tricky.

It would have been a less result-oriented study to compare ACEA C2 and C3 oils.

 

[gogydm]

The thinner oil with the lower SAPS (C1) had significantly more wear and deposits than the thicker 'mid SAPS' oil (C3).

What about that average cam wear inlet in the second slide?

 

[OVERKILL]

What about that average cam wear inlet in the second slide?

That was the first version of the test, which they found needed to be revised, because it wasn't producing accurate results.

 

[gogydm]

That was the first version of the test, which they found needed to be revised, because it wasn't producing accurate results.

Ah, makes sense. Thanks for the clarification. Well, I am glad I am trying out HPL 5W-40 in my M272 as next fill.

 

[svenson]

is there a tech sheet from that hpl 5-40 ? cant find any.