UOA's... too many variables to be reliable?

Silverado · Jan 31, 2004

One of the most important aspects of any scientific procedure is for it to be accurately repeatable. But are UOA's even scientific? I've been sucked into this site because I love technical info, but is it really that technical? With so many variables involved and no standards for sampling, how can you compare an oils performance in two different engines? Driving habits, engine condition, weather, etc. etc. How many problems are falsely blamed on the oil when its in fact an engine mechanical issue?

Also, have tests been done to see if sampling has a great affect on UOA's. For instance taking a sample 3 seconds into the drain as opposed to 15 or 20 seconds? I'm still new at this, but if I'm going to spend $20 on an oil analysis it better be somewhat reliable, and worth my time.

Not to mention that with all this new found information I'm stressing out about oil (of all things)

Jeffrey Behr · Jan 31, 2004

quote:

Originally posted by Silverado:
...if I'm going to spend $20 on an oil analysis...

Buy 6 for $54 from MTM/OilGuard

oilguard.com/oil_analysis_prog.php

[ January 31, 2004, 08:28 PM: Message edited by: rugerman1 ]

427Z06 · Jan 31, 2004

quote:

Originally posted by Silverado:
One of the most important aspects of any scientific procedure is for it to be accurately repeatable. But are UOA's even scientific? I've been sucked into this site because I love technical info, but is it really that technical? With so many variables involved and no standards for sampling, how can you compare an oils performance in two different engines? Driving habits, engine condition, weather, etc. etc. How many problems are falsely blamed on the oil when its in fact an engine mechanical issue?

Also, have tests been done to see if sampling has a great affect on UOA's. For instance taking a sample 3 seconds into the drain as opposed to 15 or 20 seconds? I'm still new at this, but if I'm going to spend $20 on an oil analysis it better be somewhat reliable, and worth my time.

Not to mention that with all this new found information I'm stressing out about oil (of all things)

(With the soundtrack of "The Matrix" playing in the background): "Welcome, to the Oil World"

Silverado · Jan 31, 2004

Thanks Morpheus

needtoknow · Jan 31, 2004

Glad you brought this up Silverado. I was afraid it would have been blaspheme (no not religious) on this site to question the use of UOA's. I did a UOA on my new Ford Ranger with 3K on the factory fill just before changing to Amsoil. I enquired about the function of such a test to Amsoil's Oil Analysis. Was told it would give a good bench mark. I'm new to this so I bit and did the UOA. Report came back with all the ingredients but nothing to say what the meaning was. I questioned Amsoil but got the, "every engine and every application is different" answer. I was trying to find if my truck was better or worse than others of similar miles. I'm trying to evaluate my present use of Amsoil so am thinking about another UOA in 6mths. What will I find, not sure if the numbers will mean any different next time. Just hoping the TBN # is good. Maybe the folks here can help.

427Z06 · Jan 31, 2004

Silverado,

Do you wish you took the other pill now?

All kidding aside, there are some regulars here who are quite articulate and reasoned that swear by UOAs, and I agree with them up to a point.

I'm convinced that UOA are a great tool, especially for determining OCIs, but I've yet to be convinced that you can predict how much less wear your getting from a particular oil/engine/climate/driving style combination.

All in all, it up to you whether you want the information provided here to turn into an obsessive/compulsive disorder or to be hobby and have fun.

JohnBrowning · Jan 31, 2004

You can not judge an oil based on UOA of different engines. THe idea is to trend your engine. If you always sample in the same manner and never change more then one variable it is as solid as can be. Most people drive the same all the time. If you are a lead foot you are not going to change your habits over night.

When two people compare two different UOA of two different engines what they are really looking at is the engine design differences and material selection etc. With this said you can still see trends as to an oils weak spots even in UOA of different engines so long as each engine has a trend to support the findines. Short of sudden failure UOA is about trending the data and looking for patterns!

427Z06 · Jan 31, 2004

Silverado,

Keeping the same theme, consider JohnBrowning the "Oracle". He has written volumes here and knows his stuff.

VeeDubb · Jan 31, 2004

quote:

Originally posted by Silverado:
[QB] One of the most important aspects of any scientific procedure is for it to be accurately repeatable. But are UOA's even scientific? I've been sucked into this site because I love technical info, but is it really that technical? With so many variables involved and no standards for sampling, how can you compare an oils performance in two different engines? Driving habits, engine condition, weather, etc. etc. How many problems are falsely blamed on the oil when its in fact an engine mechanical issue?

With enough data, those idiosyncracies such as driving habits, engine condition, etc. etc. cancel each other out. No scientific study can control for everything - I don't care what they tell you. Even a simple controlled drug study meeting all the experimental protocals still has uncontrollable factors like unobservable personal characteristics (idiosyncratic reactions to the drug, diet, exercise, stress level, etc.). But with enough data, it all cancels out.

Where we would get in trouble is if there is self selection. For example, if only racers use Redline, then even lots of data won't take away the bias. But for everyday brand names like Mobil, Valvoline, Castrol, etc., I don't see self selection as a huge issue. Probably a bigger issue for the boutique oils.

Silverado · Jan 31, 2004

My questions were not meant to slander UOA's in any way. I just want to make sure that I am not weighting other peoples UOA's too heavily. I never knew changing my oil could be this fun.....its better than an action movie. Suspense, action, drama, all in an effort to assure myself that I'm doing the best I can to take care of my engine.

My girlfriend thinks I'm nuts, but it sure does make every trip to Autozone an adventure......."No, thats the wrong 0w-30!!!!! I need the ones with the RED label!!!!"

Hoenestly, this is the best board I have ever visited. Great advice, great people, and just enough action to keep me coming back for more. Thanks!

widman · Jan 31, 2004

The real purpose of oil analisis is finding mechanical trends and changing the rate of wear, extending the life of the engine. We often find mechanical problems, issues with mechanics and their stupidity or lack of concern in procedures, system leaks, etc. and can do an immediate fix to save the life or extend it.
When it comes to using it to determine the best oil, first you have to get ahold of all the variables you can. Sample the same way all the time, same temp, etc. Control contamination (water, dirt, etc.) Once the contaminants are under control, you can try different oils it the same engine trying to maintain the same operating conditions (load, ambient temps, trip length, etc). Then you need to run enough samples to establish a trend. I ran a two year plus test in two identical (theoretically) engines that ran together side by side, sharing the load, changing and analizing the oil every 1500 hours of operation for 16,000 hours of operation. One oil averaged 4 ppm of iron per analisis and the other averaged 22 ppm of iron. Both had identical contamination. The test ended when the second engine self destructed. It is safe to conclude from this that one oil is better than the other.
Also, knowing the additive packages and their advantages as we do from this board, when I see an oil with 80 ppm of calcium, 70 ppm of zinc and 70 ppm of phos, I believe it is safe to conclude that it is inferior without long term testing.
I have done some long term testing (2+ years) that shows decisively that you can get the same wear with a good group I CI-4 oil in 400 hours between changes as Delo in 500 hours between changes.
But with the selection of oils in the US, unless you do a lot of driving and want to really stretch the change intervals, I doubt that you can identify much difference in wear between two given oils of similar quality and additive levels because of all the rest of the variables.
Although my personal preference is to run a Universal (CI-4/SL) oil where the viscosity requirements allow it. I like the extra additive level that has demonstrated such a low level of wear in many vehicles, most recently in my Toyota pickup where severe conditions and almost 7,000 km between changes only showed 10 ppm of iron (Delo).

VeeDubb · Jan 31, 2004

quote:

Suspense, action, drama, all in an effort to assure myself that I'm doing the best I can to take care of my engine.

My girlfriend thinks I'm nuts, but it sure does make every trip to Autozone an adventure......."No, thats the wrong 0w-30!!!!! I need the ones with the RED label!!!!"

Hehe....yeah, my wife thinks I'm nuts too. She couldn't understand why I stockpiled 30 bottles of GC and drove all over Columbus looking for the stuff.

The only reason I can get away with UOA's is to tell her that it is part of routine maintenance and can reveal info that no mechanic would be able to find without tear down. But I don't tell her about the action-suspense part.

427Z06 · Jan 31, 2004

quote:

Originally posted by widman:
I ran a two year plus test in two identical (theoretically) engines that ran together side by side, sharing the load, changing and analizing the oil every 1500 hours of operation for 16,000 hours of operation.

I'm curious, what do you mean by "two identical (theoretically) engines"? You had 2 engines run on test stands? Did you tear down the engines and measure all the bearings and wearing surfaces? Or did you run a simulation on paper"? In the first case, nothing statistically was proven with a sample size of one. I.e., with all do respect, you proved nothing.

[ February 01, 2004, 02:42 PM: Message edited by: 427Z06 ]

UOA's... too many variables to be reliable?

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