M1 TDT 5w40_5,235_miles_SAAB_9-5 - DISCREPANCY

[f1forkvr6]

Okay call me crazy, but my initial report showed Zinc and Phos at identical levels. The lab generously agreed to redo the test, but the differences in some of the results concern me a bit. Take a look - amended numbers for the most recent test are in [brackets]:

Code:


Oil New M1 TDT Mobil 1 TDT Castrol (GC) Castrol (GC) Univ/Avg

w/supersyn



Weight 5W/40 5W/40 0W/30 0W/30

Makup qts 1.0 0.5 0.5 0.0

Miles on oil 5,235 5,666 4,845 4,998 [5,100]

Miles on engine 84,534 79,299 58,937 54,092 [n/a]

Sample Date 09/01/08 05/24/08 03/03/07 12/01/06



Aluminum 2 [1] 2 3 3 [3]

Chromium 1 [1] 1 1 1 [1]

Iron 8 [7] 11 55 40 [22]

Copper 6 [6] 2 6 10 [5]

Lead 0 [1] 1 10 4 [6]

Tin 1 [0] 0 0 0 [1]

Molybdenm 30 [5] 11 3 6 [52]

Nickel 0 [0] 0 1 1 [1]

Manganese 1 [0] 0 1 1 [1]

Silver 0 [0] 0 0 0 [0]

Titanium 0 [0] 0 0 0 [0]

Potassium 0 [2] 1 0 2 [1]

Boron 15 [24] 30 0 6 [39]

Silicon 0 [12] 7 5 11 [8]

Sodium 1 [7] 8 15 18 [20]

Calcium 2,635 [2640] 2,453 1,588 1,778 [2,130]

Magnesium 514 [616] 446 425 468 [259]

Phosphorus 1,108 [1,180] 980 796 887 [839]

Zinc 1,108 [1,459] 1,304 932 1084 [992]

Barium 0 0 0 0 [5]



*Amended numbers in [brackets]

*for most recent

Sus Visco (210F) 72.2 70.6 64.7 63.4 s/b 65-78

cSt Visco (100C) 13.54 13.10 11.52 11.16 s/b 11.6 - 15.3

Flashpoint (F) 370 405 355 375 s/b >375

Fuel % TR b
Antifreeze % 0.0 0.0 0.0 0.0 s/b 0.0

Water % 0.0 0.0 0.0 0.0 s/b
Insolubles 0.4 0.3 0.3 0.3 s/b
TBN 4.6 4.2 3.8 3.6 S/b >1.0


Most concerning is the jump in silicone - 0 to 12! If the silicone numbers are accurate I know how to address this, but it seems to be a large variance from test to test - with the same oil sample. I know we're talking ppm values, but is this within normal test tolerances?

Moly, Boron and Sodium also show large relative percentage changes ... again, is this within test tolerance?

 

[sunruh]

if you sent your sample to blackstoned, do NOT be surprised.
heck, they can't even get a VOA from the same bottle to show the same results (sent in 3 weeks apart).

 

[f1forkvr6]

The lab was very accomodating to my query, and concerns ... this is the explanation I was given:

"No, this isn't a normal test tolerance. This sample was actually
run twice on Tuesday and then once again yesterday. On Tuesday, during the
first run, our spectrometer had some tubing problems and your sample was in
a batch of 10 that had to be rerun again due to low element readings. On
the second run, the person who did the report was entering the data and
some elements were not updated from the original run. This is a very
unusual circumstance for us and you should not run into this type of error
again."

 

[sunruh]

basically, don't trust what we send you for data, we are making this up as we go!
but we'll re-run it if you dont like the results the 1st time.

nice!

 

[demarpaint]

If you can't rely on the data, or trust the data, what is the point of the test?

Frank D

 

[Gary Allan]

This is a world wide issue ..and I do mean world wide. A survey of (something like) 100 international labs showed that few could match controls ..even after being told that they didn't "PASS" and allowed to recalibrate to exact standards. That's why trending is the real key. Using the same lab tends to give you "consistently incorrect" data.

 

[Donald]

I think OAI does a better job. Now they have 3 labs and you mail it to the one closest.

The silicon in your original run was wrong. There is always a little, never 0.

 

[Gary Allan]

Originally Posted By: Donald


The silicon in your original run was wrong. There is always a little, never 0.


Take a look - amended numbers for the most recent test are in [brackets]:

 

[f1forkvr6]

Originally Posted By: Gary Allan
Using the same lab tends to give you "consistently incorrect" data.


Which is why I'll probably use the same lab for now. I'll have somewhat accurate trending, and the service commitment to re-run my sample after I questioned it was appreciated - good customer service deserves return business and at least a second chance. We'll see where it takes me.

 

[Gary Allan]

Well, they (Blackstone and most labs for that matter) do tend to be consistent in their deviations from (each) other labs. The exception for all labs appears to be moly. That appears to go all over the place from my observations.

Blackstone is great at doing stuff over again if readings are in question. You're right. Great customer service.