SkyActiv Oil Analysis Thread

first oil change cx5 2.5NA. mazda oil w/ moly 0w20 from factory. 2724 miles on the car.

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Pretty typical for the break-in period. Thanks for sharing.
 
Here's my 6th and final UOA. This winter was a brutally cold one for us. I think the colder temps, combined with higher idle times, more stop/go and short trips is what caused the increase in Iron. Typically we don't idle as much and we take longer weekend trips, we've cut down considerably on these trips which is what has kept the mileage down. Also, just before changing, the wife went on a 6 mile trip which I think contributed to the fuel dilution as well. Unlike the other OCIs, this one didn't require a top off of any kind. Technically the others didn't require one either as I was only down 1/2 quart or less, but with Maxlife in the sump, I didn't lose any noticeable amount from the dipstick.

0 - 1,169 - Factory Fill
1,169 - 10,120 - Mag1 0w20
10,120 - 19,949 - Mobil Super Syn 0w20
19,949 - 30,031 - Mobil 1 EP 0w20
30,031 - 39,486 - SynPower 0w20
39,486 - 47,714 - SynPower 0w20
47,714 - 54,782 - Synthetic MaxLife 0w20
54,782 - Present - Citgo Supergard Synthetic 5w30

View attachment 6th UOA.pdf
 
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Here's my 6th and final UOA. This winter was a brutally cold one for us. I think the colder temps, combined with higher idle times, more stop/go and short trips is what caused the increase in Iron. Typically we don't idle as much and we take longer weekend trips, we've cut down considerably on these trips which is what has kept the mileage down. Also, just before changing, the wife went on a 6 mile trip which I think contributed to the fuel dilution as well. Unlike the other OCIs, this one didn't require a top off of any kind. Technically the others didn't require one either as I was only down 1/2 quart or less, but with Maxlife in the sump, I didn't lose any noticeable amount from the dipstick.

0 - 1,169 - Factory Fill
1,169 - 10,120 - Mag1 0w20
10,120 - 19,949 - Mobil Super Syn 0w20
19,949 - 30,031 - Mobil 1 EP 0w20
30,031 - 39,486 - SynPower 0w20
39,486 - 47,714 - SynPower 0w20
47,714 - 54,782 - Synthetic MaxLife 0w20
54,782 - Present - Citgo Supergard Synthetic 5w30

View attachment 220717

Looks like a little dilution issue at your 2/3/17 analysis (more so than your current one), with only Trace amounts in the analyses during the warmer months. I guess that makes sense, huh? Seems like evaluating oil performance needs to take seasonality into account, however one might adjust for that.

Was the TBN your only option added to the Standard Test? Did you have an idea as to where TBN should have started out?

I've never had this done, but in the age of GDI engines, I can see the value. It was the oil dilution issue that caused me to run away from Hondas and buy a Mazda. And reading stories on other sites, I see folks claim that they were able to take the report into dealers to have major warranty work done that might have otherwise gone unnoticed (trace antifreeze in the oil due to warped heads in one case).

Interesting stuff...
 
Was the TBN your only option added to the Standard Test? Did you have an idea as to where TBN should have started out?

Yes, TBN is all I added to the analysis.

According to PQIA, a SynPower VOA on 3/6/17 showed a virgin TBN of 8.88. SynPower isn't the exact same as the MaxLife variant I used, but is be quite similar so the TBN shouldn't be far off if at all.
 
Yes, TBN is all I added to the analysis.

According to PQIA, a SynPower VOA on 3/6/17 showed a virgin TBN of 8.88. SynPower isn't the exact same as the MaxLife variant I used, but is be quite similar so the TBN shouldn't be far off if at all.

Interesting that the TBN looks consistently strong.
 
Interesting that the TBN looks consistently strong.

Ironically enough, PQIA just published new results yesterday. One of them was Valvoline Synthetic MaxLife, virgin TBN is 9.16. The formulation has changed a bit compared to what I used, but I think it's a safe bet that the virgin TBN of what I used was around 9.
 
Ironically enough, PQIA just published new results yesterday. One of them was Valvoline Synthetic MaxLife, virgin TBN is 9.16. The formulation has changed a bit compared to what I used, but I think it's a safe bet that the virgin TBN of what I used was around 9.

So much minutia to wade through in life.

As I understand it, the "B" in TBN (Base) fights off the acids in the oil so as to preserve the oil's lubricating properties...it has no other function, and "too much" of it does no harm. So starting off with a higher number may or may not be of value, since all that is required is "enough" to neutralize the acid that's present.

I find it interesting that the Base is consumed quickly, then levels off, and then decays slowly. Makes one wonder exactly what is going on in there...chemically speaking. I wonder if there's a consistent amount of Base consumed over running time, such that those oils with a higher starting number could be used longer before approaching a level of 1.

Then you wonder how many of those metals are a byproduct of combustion, and how many are shards of motors.
 
I find it interesting that the Base is consumed quickly, then levels off, and then decays slowly. Makes one wonder exactly what is going on in there...chemically speaking. I wonder if there's a consistent amount of Base consumed over running time, such that those oils with a higher starting number could be used longer before approaching a level of 1.

What makes up the TBN is equally important as the TBN itself. Even 8 or so years ago you'd see some of the top tier synthetics pushing TBNs of 12. Now, they're almost always in the 8-10 range, typically on the lower end. As base oils improve and additive technology improves, I think we'll see a lower starting TBN because TBN retention is stronger.
 
What makes up the TBN is equally important as the TBN itself. Even 8 or so years ago you'd see some of the top tier synthetics pushing TBNs of 12. Now, they're almost always in the 8-10 range, typically on the lower end. As base oils improve and additive technology improves, I think we'll see a lower starting TBN because TBN retention is stronger.

I wonder if that means a future like-kind decrease in Acceptable Minimums on the reports.

This thread has caused me to go do some reading on the subject of oil analyses. Many articles claim that except for diagnosing a specific one-time issue, they provide no value (mostly because--like "the best fuel for my car"--we don't drive in repeatable controlled laboratory conditions.) But for what amounts to the cost of an extra couple of gallons of gas per month, there's lots of good info to be had in each discrete report as well as with the trends.

For instance, I was looking at the correlation between Fuel%, Flashpoint and Viscosity (assuming they are all affected by Dilution). No conclusions, just looking at it and wondering if some oils might be less susceptible to dilution, or if the timing of topping off the oil affects it (1/2 quart soon before the next oil change could bump the numbers.)

I also noticed that the Values Should Be column for properties only apply to the then-current sample. Have they changed for you from report to report? They're obviously not driven by past data/averages (no viscosity samples came anywhere near the high end of their "Should Be" ranges). And they are the same on your 55,000 mile report as they are on the 2,700 report CZ5GT posted.
 
For instance, I was looking at the correlation between Fuel%, Flashpoint and Viscosity (assuming they are all affected by Dilution). No conclusions, just looking at it and wondering if some oils might be less susceptible to dilution, or if the timing of topping off the oil affects it (1/2 quart soon before the next oil change could bump the numbers.)

I'm not entirely sold on this point. Most UOAs I've seen show a correlation between flashpoint and fuel dilution. For instance, here is a graph just from my experience. Trace results were given a value of 0.2.

Fuel Dilution Trendline.PNG
 
I also noticed that the Values Should Be column for properties only apply to the then-current sample. Have they changed for you from report to report? They're obviously not driven by past data/averages (no viscosity samples came anywhere near the high end of their "Should Be" ranges). And they are the same on your 55,000 mile report as they are on the 2,700 report CZ5GT posted.

I looked into this and got some good information from Blackstone. While I don't agree with their methodology, they were open and honest about how they come up with these values. Essentially, they use information from the PDS for the particular oil being analyzed. More information and a small discussion can be found here.
 
I looked into this and got some good information from Blackstone. While I don't agree with their methodology, they were open and honest about how they come up with these values. Essentially, they use information from the PDS for the particular oil being analyzed. More information and a small discussion can be found here.

Thanks for circling back.

I just read that BITOG thread. Blackstone is open about their methodology, but as you and others point out, some of it makes no sense.

In reading this stuff, I find lots of rabbit holes within which one might get lost. And my "Applies Only To The Current Sample" questions still hang out there.

One would think things like Fuel%, Antifreeze% and Water% should have absolute thresholds, not changing ones. In fact, all of the "Applies Only To The Current Sample" ranges are identical on the analysis posted by Kedis82ZE8 in Comment #1 in this thread, the one posted by Triton46 in Comment #39 in this thread, and in the analysis you posted.

So I went and looked at a December 2016 report posted by a guy for his Scion, and the viscosity "Applies Only To The Current Sample" ranges are different from the three CX-5 reports posted here. This somewhat supports the observation that these reference ranges are pulled from Blackstone's historical database of analyses from identical models (engines?).

So maybe that's what they mean when they say "Applies Only To The Current Sample." Perhaps a more accurate statement might be "Specific To This Make & Model" (or maybe "Specific To This Engine", since everyone's model year is different) And if what I read is correct, it only tells you how you fare relative to similar vehicles/engines (pulled from their analysis database), as opposed to being a discrete standard. (And note that some BITOG folks point out that the PDS for oils lists a viscosity number, not the range that Blackstone cites).

Here's how those "Values Should Be" for the CX-5 and the SCION compare:

Same for the three CX-5s, Scion is different
SUS Viscosity
cST Viscosity

Same for the three CX-5s and for the Scion
Flashpoint
Fuel%
Antifreeze%
Water%
Insolubles%

It seems as though Viscosity "Should Be" is the only value that varies by model and the others ARE universal discrete standards. Maybe.

As I said, lots of rabbit holes.
 
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Got an analysis for my 2.5T from oil analyzers... aaaand 5% fuel in 3350 miles.. ouch! (nailbyt)
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The oil happened to be a cheap Castrol GTX magnatec. If I understand correctly, it should not affect fuel levels? Better oil should have just maintained the viscosity better.
Possibly more relevant fact was that I ran only 87 gas this time, as a low interval experiment :)
Switching to 91 and AmsoilOE, will check again in 3500.

At the same time got a report for a q5 with 70+k miles. Only 1.6% over 9500 miles. Most of the mileage was rough due to carbon buildup.
 

That's not good.

I saw your comments over there that using 87 octane should have no effect on oil dilution. Weren't there other comments here stating that 93 should help with dilution because of how the timing changes in response to it?

I gotta go out and smell my dipstick tomorrow morning...
 
That's not good.

I saw your comments over there that using 87 octane should have no effect on oil dilution. Weren't there other comments here stating that 93 should help with dilution because of how the timing changes in response to it?

I gotta go out and smell my dipstick tomorrow morning...
Based on Mazda's official power curve, the horsepower and torque are exactly the same under 4,000 rpm between 87 and 93 octane. Retarding of timing may happen more frequently on 87-ocatna gas when engine is encountering heavy load, hence there's some advantage here with 93-octane gas. For everyday driving 93-octane gas won't give you any better performance under 4,000 rpm. If you don't use manual shift or Sport Mode on your 6-speed automatic, you can hardly make your engine revving over 4,000 rpm, hence Mazda published both power curves for 87 and 93-octane gas to "prevent unnecessary spending on premium fuel".

87 or 93, retarding timing alone won't cause any oil dilution issue.
 
Just got my first UOA after the last oil change at ~90K miles, with about ~6K on the last fill of Mazda Moly oil. Looks like a pretty excellent report, and they suggest going 8K miles next time!

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Just got my first UOA after the last oil change at ~90K miles, with about ~6K on the last fill of Mazda Moly oil. Looks like a pretty excellent report, and they suggest going 8K miles next time!

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One can always tell from a UOA report that if the Molybdenum content is very high at ~650+, it must be from Mazda moly oil.
 
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