Data Challenge!! UOA Trends 7yr / 100k

[OVERKILL]

It’s not all wear caused by lubricants in use. We are taking parts per million- and even some of those low amounts are metal sloughing from any surfaces the oil merely contacts for example.

Kschan says it even more clearly

Yep. A UOA cannot differentiate between corrosion, oxidation or actual mechanical wear. Polar compounds naturally displace molecules from the surface for example, and these will show up in a UOA, while mechanical wear that liberates particles above 5 microns won't be seen.

 

[JZiggy]

Yep. A UOA cannot differentiate between corrosion, oxidation or actual mechanical wear. Polar compounds naturally displace molecules from the surface for example, and these will show up in a UOA, while mechanical wear that liberates particles above 5 microns won't be seen.

So in short, despite the 14 data points, there is no way to draw useful conclusions about optimizing oil selection or OCI?

 

[kschachn]

So in short, despite the 14 data points, there is no way to draw useful conclusions about optimizing oil selection or OCI?

You really want this, don't you?

 

[Pablo]

So in short, despite the 14 data points, there is no way to draw useful conclusions about optimizing oil selection or OCI?

As you can see throughout this site this legitimate logical thinking doesn’t stop people from commenting or trying. It’s kinda fun!

 

[OVERKILL]

So in short, despite the 14 data points, there is no way to draw useful conclusions about optimizing oil selection or OCI?

You can optimize OCI length, and oil choice for that parameter, but not for "wear".

 

[JZiggy]

You really want this, don't you?

Well, I like data and like putting it to use. But it sure sounds like the science is settled and there's nothing to talk about.

You can optimize OCI length, and oil choice for that parameter, but not for "wear".

Is there a better proxy for "wear," or is it a black box?

 

[OVERKILL]

Is there a better proxy for "wear," or is it a black box?

I mean, without a controlled test verified with tear-downs, no, there really isn't.

 

[kschachn]

Is there a better proxy for "wear," or is it a black box?

It’s not a black box but it isn’t a cheap UOA either. A quick search shows tests such as ASTM D7320, D8279 and D6709.

You need a laboratory to see comparative wear between motor oils. It’s just too small otherwise and disappears into the noise in a UOA.

 

[Oliveoil2]

This Toyota engine design just doesn’t care if you run a 20, 30, or 40 in it. It is one of the most durable engines made. Low reviving. It is very easy on oil. You’ve done well. Don’t over think it.

 

[SubieRubyRoo]

Yep. A UOA cannot differentiate between corrosion, oxidation or actual mechanical wear. Polar compounds naturally displace molecules from the surface for example, and these will show up in a UOA, while mechanical wear that liberates particles above 5 microns won't be seen.

You mean to say that the “using Mobil 1 increases my iron wear” crowd has to find a new boogeyman now?!? We’ve tried to tell them for years about the polarity issues when changing brands…

 

[SubieRubyRoo]

So in short, despite the 14 data points, there is no way to draw useful conclusions about optimizing oil selection or OCI?

You’ve got some great trends that show nothing out of the ordinary (but identifying normal wear isn’t measurable) in your engine with 300k and going. That alone, plus the fact that two of those oils aren’t even marketed anymore… I think you found your engine’s winner. There’s no need to fret or worry. Buy a bunch of it, preferably on sale, and your vehicle should carry on for a looooong time!

 

[JZiggy]

Thanks ya'll. I know the engine is wearing well, so definitely not an attempt to overthink it out of worry or fretting -- it's just fun!

Blackstone was kind enough to answer an email from me about this topic. Based on our interaction it still seems that optimizing for minimal ppm-per-mile (specifically for Iron) is worthwhile in an attempt to minimize engine wear.

The question then becomes are the UOAs accurate enough and does the data support concluding that a particular variable can impact the ppm/mi in a statistically significant way. The consensus here seems to be in general it's not possible to draw any meaningful conclusions.