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Discussion Starter · #1 ·
Here's a screen cap I took of my first UOA at 6500 miles, along with an Eco UOA at 6500 and another LS UOA at 6500. The order is:

Rocco611's 2012 Eco --> ScaredPoet's 2011 LS --> My 2014 LS

comparison.png

So I'm wondering, which of these would you prefer to see on your car? I think ScaredPoet's is the worst (middle). He must have been doing heavy city driving and he said his OLM was still at 50%! I guess the OLM sucked in 2011.

Also, which elements do we want to see? I guess that some of these, like Boron, are helpful additives and we want to see large numbers, right? Is Calcium an additive? What about Phosphorous?

I drive gently so I'm glad the UOA looked good. This was at 16% on the OLM.
 

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None of those engines are finished breakin in yet, so your wear metal comparison is useless. That is, unless you neglected to provide them the unit mileage.

If anything, your shearing may be worth comparing, but not only did you crop that out in the picture, but you used Blackstone, which doesn't reliably test for fuel dilution so you wouldn't know the cause of the shearing anyway.
 

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Discussion Starter · #3 ·
Wow, what a kind, courteous, insightful reply. I'll tell you who I won't be ordering any oil from. This guy ^

I'll go ahead and answer my own question, after some research. Boron, phosphorous, moly, and calcium are related to additive packages, so the high levels that I saw are a good thing.
 

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Wow, what a kind, courteous, insightful reply. I'll tell you who I won't be ordering any oil from. This guy ^

I'll go ahead and answer my own question, after some research. Boron, phosphorous, moly, and calcium are related to additive packages, so the high levels that I saw are a good thing.
You must have graduated from the school of sarcasm with high honors. :p

As I noted, oil analysis reports from so early on in the drain interval are worthless for comparing wear metals because everything is skewed by break-in material.

Phosphorous is one of the reactive elements in ZDDP, along with Zinc. They are EPA mandated to 700ppm and 800ppm respectively for all API SN oils, and I have on a number of occasion seen a 50ppm-100ppm margin of error with Blackstone labs so they aren't even worth mentioning. It is inconsequential because all API SN oils will have it. I've been taking, analyzing, and interpreting oil analysis reports for the past 1.5 years, so don't assume I wasted my breath in my reply.

Boron is an anti-friction additive that depletes with mileage. Jury is out on whether or not it's a good thing. On one hand, it reduces friction and improves fuel economy. On the other hand, it extends the break-in process by improving the boundary lubrication of the oil where microscopic ridges would have otherwise been (and will be) flattened.

Molybdenum is an extreme-pressure/anti-wear additive similar to (but not as effective as) ZDDP. Since ZDDP levels are mandated to the aforementioned limits, Molybdenum is included to further improve boundary lubrication. Do you need an overview of the difference between hydrodynamic and boundary lubrication?

Calcium is a detergent, which contributes to the oil's TBN; its ability to neutralize acids. TBN decay is nonlinear, and there are varying kinds of Calcium-based detergents, all of which are proprietary formulations. This makes comparisons of Calcium concentrations in oils useless.

Looking at your oil analysis reports, assuming they are taken during the break-in cycle, the only point of relevance is the viscosity of the oil. I alluded to this briefly, and will explain. Blackstone Labs tests fuel dilution according to flash point. The concept is that the low flash point of fuel will reduce the high flash point of oil and identify fuel dilution. In practice, both base oil and VI improver shearing will also reduce its flash point, thus making it impossible to accurately measure fuel dilution using this method. If the oil thinned, you will not know if the oil itself sheared or if there is fuel dilution. We've seen a discrepancy of over 4% between Blackstone's estimated fuel dilution method and Polaris' gas chromatography method.

Is that more insightful? If not, refer to post 10 in the following thread, written by yours truly, the rude, uninsightful, unkind admin that has spent the last 1.5 years studying toward an STLE CLS certification:

http://www.cruzetalk.com/forum/34-1-4l-turbo/79866-1-4t-used-oil-analysis-thread.html
 

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Discussion Starter · #5 ·
Alright, thanks. If you ever could directly compare three oil changes from different vehicles, this is it. Same lab, same mileage, same oil, same vehicle life.
 

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Alright, thanks. If you ever could directly compare three oil changes from different vehicles, this is it. Same lab, same mileage, same oil, same vehicle life.
Would you mind posting the complete report for each of those? The TBN report on the 2nd analysis concerns me. If you'd like, you can send them to me by e-mail and I can edit out the personal information so they aren't posted publicly.
 

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I ignore the Blackstone comments most of the time because they are all too often useless and incorrect (re: fuel dilution). I don't really care for comments like "nice engine" and, in the case of a sheared oil, "this oil is holding up great." I can interpret my own analysis. I only read them this time because the report was truncated.

I've seen people hit a TBN of 0.5 with our oils before, but that was on crazy long drain intervals. I mean nearly 24k miles on our cheap OE oil. At least on that one, Blackstone's comments were amusing. "Did you really run this oil 23,616 miles? This may be some sort of record." A TBN of 0.1 is highly unusual, even for the GM oil at that interval. I wonder if the factory fill is a significantly different formulation from the GM dexos1 re-fill. I changed my factory fill out at 5,500 and used a variety of synthetics since then, with the last change being a switch to AMSOIL.

For 2013+ models, GM re-calibrated the oil life monitors to have people change their oil far sooner than on 2011-2012 models. My 2012 Cruze Eco took 10,185 miles to hit 0% on the OLM.
 
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