GM 6.0L L96 at 66k; various 30 grade oils - AMS SIG, OE, Napa SYN

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This is from my L96 GMC 3500 CC, 4wD. This truck is used under heavy service, a bunch of towing 12000 lbs over varying terrain. A few things of note........

Red column is AMS Signature Series 5w30. This 5500 mile run included two RV trips to NC mountains and NC beach. Various high way and city driving, I suppose average cruising RPM was 3000, loaded. Not sure of the actual full loaded miles

Blue and Yellow column are AMS OE, and Napa Syn, 5w30. Both with various city and highway, towing my 12-13k gooseneck with my excavator, along with unloaded trips also. Not sure of the actual full loaded miles.

OCI for the Napa syn was 5-5.5k, just forgot to write it on the test sheet when i sent it off.

If there are any questions or comments, let me know
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Props to you for doing TBN. Not enough people do it IMO.
TBN is one of only a handful of actually useful data when considering a single OA. The others are viscosity, potassium, silicon, fuel %, and iron. The rest are still pieces of information but leave too much subjectivity to their interpretation.

One could be expected to say from these UOAs that Amsoil SS is the worst and Napa the best, but that would be foolish and a misuse of the data. With 3 back-to-back-to-back formula changes, all one could say that is backed up by data is that all of the oils remained in grade and had sufficient TBN remaining at the drain point.

OP, if you intend to ever discern more from your UOAs, you need to stick to the same oil formula for at least 3 UOAs so the composition will stabilize and not skew your data.
 
Good for others to see the results. Many post "feelings" about their choice of motor oils. This is cold hard facts. Interested to know what many of these numbers mean, and which is actually better. I suppose one thing that viewers must do is trust that my testimony is true with the usage and such.

Seems to me that the Amsoil Signature Series is the best of the 3. Not an expert though.
 
TBN is one of only a handful of actually useful data when considering a single OA. The others are viscosity, potassium, silicon, fuel %, and iron. The rest are still pieces of information but leave too much subjectivity to their interpretation.

One could be expected to say from these UOAs that Amsoil SS is the worst and Napa the best, but that would be foolish and a misuse of the data. With 3 back-to-back-to-back formula changes, all one could say that is backed up by data is that all of the oils remained in grade and had sufficient TBN remaining at the drain point.

OP, if you intend to ever discern more from your UOAs, you need to stick to the same oil formula for at least 3 UOAs so the composition will stabilize and not skew your data.
I agree. The iron in the SS sample could be remnant of the oil change previous, or fault in filter or whatever. I did this test to see if what was generally closest to claims, and product data sheets. The SS seems to hold to its claims. The prvious oil before the SS was Valvoline or Napa cant remember. i think I am going to Use the SS for the next few to see if the iron and such cleans up on the second or third.......again, not an expert. Thanks.
 
TBN is one of only a handful of actually useful data when considering a single OA. The others are viscosity, potassium, silicon, fuel %, and iron. The rest are still pieces of information but leave too much subjectivity to their interpretation.

One could be expected to say from these UOAs that Amsoil SS is the worst and Napa the best, but that would be foolish and a misuse of the data. With 3 back-to-back-to-back formula changes, all one could say that is backed up by data is that all of the oils remained in grade and had sufficient TBN remaining at the drain point.

OP, if you intend to ever discern more from your UOAs, you need to stick to the same oil formula for at least 3 UOAs so the composition will stabilize and not skew your data.
I don't disagree, and too many people in our UOA section miss out on getting TBN.
 
I don't disagree, and too many people in our UOA section miss out on getting TBN.
TBN is very important from my understanding...........I suppose that all things being equal, all the other numbers could be good, but TBN at 0 would kill all the "goodness" of the other numbers. Again, not an expert, but it would seem to me that the more well rounded an oil, the better. And from my research, TBN is one of the most important, at least when it comes to oil life.

The TBN cost is not much, 10$. I would not do this every OCI, but I think that the SS could have gone much longer, how long? who knows maybe twice as far as the others?
 
Good for others to see the results. Many post "feelings" about their choice of motor oils. This is cold hard facts. Interested to know what many of these numbers mean, and which is actually better. I suppose one thing that viewers must do is trust that my testimony is true with the usage and such.

Seems to me that the Amsoil Signature Series is the best of the 3. Not an expert though.
The fact is that you have a well operating engine that produces a good UOA. It tells nearly nothing about the performance of the oils. There is nothing that you can draw from that spectrographic analysis that would allow you to conclude that one oil is better than the other.
 
The fact is that you have a well operating engine that produces a good UOA. It tells nearly nothing about the performance of the oils. There is nothing that you can draw from that spectrographic analysis that would allow you to conclude that one oil is better than the other.
Nothing? Really? How so? And if not, then how?
 
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Nothing? Really? How so?
Because UOAs only look at elements <7 microns. Your engine could actually be experiencing a catastrophic failure, shedding large chunks instead of a fine slurry, and a UOA would never alert you.

UOAs are only truly useful for viscosity, TBN, coolant/dirt/fuel on a “snapshot” basis. Other, much more expensive tests (ferrography, for one) are required to determine what components are wearing from what’s left in the oil. UOAs only really give you information about the oil, even though speculation about what it tells you is rampant. About the only element you see in a UOA that’s useful is Iron, and that’s at a condemnation level of >150ppm per Doug Hillary.
 
I don't disagree, and too many people in our UOA section miss out on getting TBN.
I like seeing TBN, but it costs extra (at least with Blackstone) and IMO not very useful unless the OCI is >5000 miles. I would never complain at or guilt someone into spending extra money on something that is not useful to them just because *I* want to see it.
 
That NAPA syn with 255 moly, wow! Otherwise, looks like a ~5K OCI for a gas engine that gets a workout is always a good idea, wish I could convince the penny pinchers at my company that, they apparently like replacing engines...
 
Because UOAs only look at elements <7 microns. Your engine could actually be experiencing a catastrophic failure, shedding large chunks instead of a fine slurry, and a UOA would never alert you.

UOAs are only truly useful for viscosity, TBN, coolant/dirt/fuel on a “snapshot” basis. Other, much more expensive tests (ferrography, for one) are required to determine what components are wearing from what’s left in the oil. UOAs only really give you information about the oil, even though speculation about what it tells you is rampant. About the only element you see in a UOA that’s useful is Iron, and that’s at a condemnation level of >150ppm per Doug Hillary.
Yes this. All those things are useful but they aren't discriminating oil quality. TBN maybe but even then is that an issue these days with low sulfur fuels and the typical low OCI intervals?
 
Because UOAs only look at elements <7 microns. Your engine could actually be experiencing a catastrophic failure, shedding large chunks instead of a fine slurry, and a UOA would never alert you.

UOAs are only truly useful for viscosity, TBN, coolant/dirt/fuel on a “snapshot” basis. Other, much more expensive tests (ferrography, for one) are required to determine what components are wearing from what’s left in the oil. UOAs only really give you information about the oil, even though speculation about what it tells you is rampant. About the only element you see in a UOA that’s useful is Iron, and that’s at a condemnation level of >150ppm per Doug Hillary.
I see. That makes sense.

So by that, I suppose you can never REALLY know.....you can think you know, but not really until the death of the machine. Again, the purpose of this was to check claims on AMS products and stated claims.

It seems like the TBN is high from the get go, perhaps I should have tested a virgin sample...
Viscosity is still almost dead nits in the middle of the range.....
A bunch of anti wear elements
It’s extremely similar to Valvoline Advanced full syn.
You have the analysis?
 
Understand all.....

this is not a sales thing or to boast anything over the other. Just figured posting this info would be helpful to some........and free to a point, to the reader. This info is worth $120. Wish more would post results
 
I see. That makes sense.

So by that, I suppose you can never REALLY know.....you can think you know, but not really until the death of the machine. Again, the purpose of this was to check claims on AMS products and stated claims.

It seems like the TBN is high from the get go, perhaps I should have tested a virgin sample...
Viscosity is still almost dead nits in the middle of the range.....
A bunch of anti wear elements

You have the analysis?
It’s not really disputed here that Amsoil is a very good product, even its lower tiers (OE, XL) but the thing to remember is the UOA is really only to verify the oil is still serviceable. The “nice” thing you can rest easy about is when a certification or spec is required for your engine and you use an oil that is actually approved by that cert or spec, that there should be no appreciable differences between oil “A” all the way to oil “Z”, provided you change it on time and keep the level full.

@dnewton3 has many good posts detailing that even conventional oils protect just fine; use the UOA to make sure, for your OCI, that viscosity is in the correct range, that TBN is still above 1.0 minimum, and go from there. Remember that good air filtration makes an oil filter (and your UOAs) look better, so you can’t neglect any part of the maintenance. After that, buy what makes you happy 👍🏻
 
You have the analysis?

I mean, there are quite a few in the UOA forum:




And the NAPA oil is made by Ashland (Valvoline)
 
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