One Oil - Two Labs - Two Different Results

[Nyati]

I wrote this Oil Analysis report about my Mercedes 500SL:

500SL

I had a Blackstone Kit and a Wix Kit and figured I may as well try them both. I took the Oil Sample and mixed it throughly back and forth between two sample bottles and sent one to each lab. I got the Blackstone report back quickly and used it to make the report. I got the Wix one back today. They are similar except they are significantly different on Aluminum.

It's like have two watches. If you only have one - you know what time it is. If you have two that are 10 minutes apart - you have no idea.

 

[Clevy]

Awesome. So as per blackstone themselves oil doesn't have an expiration date.
So all those guys who say they change their oil yearly regardless of miles should now know the habit is absurd.

These 2 reports confirm that a used oil analysis is only to see if oil is serviceable and not to be used as wear check which many here commonly try to do when comparing oils.

Thanks for posting.

And lest all say it together now OIL DOESNT HAVE AN EXPIRATION DATE.

 

[novadude]

Aside from aluminum, those two reports look really close. Pretty significant differences on Zinc too (~20%).

I guess the moral is that we shouldn't get too excited arguing over whether one oil is better than another based on 1000 pm zinc vs 1050 ppm zinc.

 

[friendly_jacek]

Originally Posted By: Nyati

It's like have two watches. If you only have one - you know what time it is. If you have two that are 10 minutes apart - you have no idea.


You average the time between the two watches and you are good to go. Alternatively, throw away the watches and check time on your cell phone.

 

[MikeySoft]

Do 3 UOA then take a vote.

I had a similar experience when I used 3 different labs on the same oil as reported here: http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3044859

I first used Caterpillar and NAPA (ALS). I think ALS also does WIX but not sure. Caterpillar and ALS were very similar except for fuel. CAT had very high fuel in the oil. So much so that they told me to demand Honda fix it. However, the high fuel dilution did not agree with CAT's normal cSt. I then did a Blackstone UOA. Blackstone confirmed I did not have a very high fuel dilution. However Blackstone had a lower AL compared to the other two. This is similar to the AL Blackstone found in yours.

 

[gpshumway]

Having recently switched from Blackstone to Polaris, and also trying to track down high Al readings in my Honda, this makes me wonder. Three ppm to 22ppm is a big difference, especially for a metal which does not generally show double digit readings the way Iron often does.

 

[Spector]

UOA, need a huge grain of salt when interpreting the results!

One of the reason I gave up doing them years ago.

 

[mongo161]

Whats the most you ever lost in a coin toss?

Flip a coin and call it.

 

[k24a4]

I had a similar experience. My first UOA was Blackstone, and reported 3ppm Al. My second was WIX (ALS) and reported 14ppm Al. This was not on the same oil or oci, however.

Even though the Al was higher with ALS I have seen it trend downward with different oils.

ALS here

Blackstone here

In a future UOA I may do the same as you, send the sample off to both labs to see if there is a discernible difference.

Thanks for posting your result.

 

[aaonms]

My 2¢ would be to pick a lab and then use the given numbers as a reference point. Only become concerned if/when you see creep away from the established trend.

 

[Ayrton]

I think it is reassuring to see the labs are similar.

Aluminum is definitely the catch to that. I may give a Wix kit a try in the coming months and I will take the aluminum reading with a grain of salt, if it reads higher than expected.

It's awesome Wix gives the TBN for the price, but a bummer you don't get flashpoint.

Nyati - I really appreciate you posting both! I think you can feel good in both of your UOAs. Both are very good overall.

I'd trust the aluminum is closer to Blackstone's though.

 

[Voltmaster]

I wouldnt call these two reports too diffrent... they are very close.

 

[Vikas]

why not send it to the same lab? I bet the results would be still different. that should tell you how much weight you need to put in to UOA.

 

[SteveSRT8]

^^^yep, around here the reverence is not deserved. You need a handful on the same rig across some miles to be able to infer anything at all, much less get any real info about the engine's condition...

 

[Shannow]

Great information, thanks.

Pertinent to the VI discussions on Gokhan's TGMO oil analysis...both KV100s here are "correct", in that the difference between them is within the error range of the typical viscometers, but they are nearly 0.4cst apart...assuming same KV40, VI are 5% different...on the same oil

(someone still owes me $100 site sponsor over that one).

 

[HKPolice]

Is it possible that WIX contaminated the sample when they were handling it? All discrepancies read higher with WIX, even the viscosity rating.

 

[bulwnkl]

Maybe learning a little about the metallurgy in the unit in question would clarify which lab's numbers are 'reasonable?'

 

[MolaKule]

Originally Posted By: bulwnkl
Maybe learning a little about the metallurgy in the unit in question would clarify which lab's numbers are 'reasonable?'

For sure as different engines may have different metallurgy in their components.

And providing a New Oil Analysis (VOA) is important as well since lube manf. are changing formulae like changing underwear.

 

[MikeySoft]

I used 3 labs on the same oil here. one oil, 3 labs

They were all different in ways. Blackstone was low in AL. A differ one was way way off in fuel, so much so they they told me to take it to the dealer to get if fixed.

 

[GaleHawkins]

Mikey you sold me on not starting to get lab reports.

If I had engines that held gallons of oil and where critical to business I would do the reports. When the report costs more than new oil and filter I just dump and go.