M1 0W40 Calcium Levels

[The Critic]

I just received a UOA on a fill of M1 0W40 where the Calcium level was 3687ppm. I was surprised by this number, so I had the lab retest - and it remained about the same: https://bobistheoilguy.com/forums/threads/2016-mb-e350-mobil-1-0w40-18-092-miles.370385

I found a VOA from 2020 where the Calcium level was 3437ppm: https://bobistheoilguy.com/forums/threads/mobil-1-0w40-euro.332273/

I also found an UOA from 2022 where the Calcium level was 3771ppm: https://bobistheoilguy.com/forums/t...4k-mi-oci-144k-mi-2013-cadillac-cts-v.364117/

However, most UOA's I've seen show the Calcium level to be about 3000ppm. Was there a brief time period where M1 0W40 was using ~3500ppm of Calcium in its formulation?

 

[BMWTurboDzl]

Variations between different labs?

 

[RDY4WAR]

Between variances in blending, methods of sampling, and margin of error of the ICP, it can vary quite a bit. A +/-15% swing isn't unrealistic between different batches tested in different machines. The ICP alone is +/-5% with good calibration, thorough flushing/cleaning, and slower, more precise measuring method. The ICP at the UOA labs, shooting samples through as fast as possible, can fair worse, plus possible carryover from previously run samples.

 

[himemsys]

There are two VOAs in my database, both from 2020. One is 3247 (Blackstone) and the other is 3437 (Oil Analyzers).

 

[weaponoffreedom]

There are two VOAs in my database, both from 2020. One is 3247 (Blackstone) and the other is 3437 (Oil Analyzers).

maybe before they changed to SP?

 

[SynOilFan]

I posted a VOA of the latest SP 0w-40 in the VOA section

 

[edyvw]

I just received a UOA on a fill of M1 0W40 where the Calcium level was 3687ppm. I was surprised by this number, so I had the lab retest - and it remained about the same: https://bobistheoilguy.com/forums/threads/2016-mb-e350-mobil-1-0w40-18-092-miles.370385

I found a VOA from 2020 where the Calcium level was 3437ppm: https://bobistheoilguy.com/forums/threads/mobil-1-0w40-euro.332273/

I also found an UOA from 2022 where the Calcium level was 3771ppm: https://bobistheoilguy.com/forums/t...4k-mi-oci-144k-mi-2013-cadillac-cts-v.364117/

However, most UOA's I've seen show the Calcium level to be about 3000ppm. Was there a brief time period where M1 0W40 was using ~3500ppm of Calcium in its formulation?

In PDS you will see language: typical values.
Different batches can produce different results.

 

[RDY4WAR]

We're talking about parts per million here. Look at 3000 ppm and 4000 ppm as 0.3% and 0.4% respectively of the oil's total content. Comparing the VOA and UOA in the OP, that's 0.3437% vs 0.3771%.

 

[The Critic]

In PDS you will see language: typical values.
Different batches can produce different results.

We're talking about parts per million here. Look at 3000 ppm and 4000 ppm as 0.3% and 0.4% respectively of the oil's total content. Comparing the VOA and UOA in the OP, that's 0.3437% vs 0.3771%.

That's beside the point - almost every other M1 0W40 UOA is at 3000ppm. Something is amiss here.

 

[edyvw]

That's beside the point - almost every other M1 0W40 UOA is at 3000ppm. Something is amiss here.

Again, it could be a batch, left over oil etc.
Different labs could return different results.
I would not bet on $30 lab analysis as being dead accurate.

 

[The Critic]

Again, it could be a batch, left over oil etc.
Different labs could return different results.
I would not bet on $30 lab analysis as being dead accurate.

We're talking about being off by more than 15% - over 500ppm difference.
I'm the first to admit that UOA's are of questionable accuracy, but they're generally not this bad - especially if the sample was ran twice.

 

[Leo99]

We're talking about being off by more than 15% - over 500ppm difference.
I'm the first to admit that UOA's are of questionable accuracy, but they're generally not this bad - especially if the sample was ran twice.

I can tell that you're a chemist and not a microbiologist. LOL.

I look at chemistry results on drugs on a regular basis. Between the method variability, the blending variability, the in-use variability, +/- 15% seems about the best that can be achieved on a UOA. Nothing about these results makes me think there is any lab error or excessive method variability. I'd be surprised if they performed the extensive method validation and change control management and instrument calibrations that we perform for drugs.

 

[chris719]

I can tell that you're a chemist and not a microbiologist. LOL.

I look at chemistry results on drugs on a regular basis. Between the method variability, the blending variability, the in-use variability, +/- 15% seems about the best that can be achieved on a UOA. Nothing about these results makes me think there is any lab error or excessive method variability. I'd be surprised if they performed the extensive method validation and change control management and instrument calibrations that we perform for drugs.

it depends on the method, instrument, sample prep, etc. of course. I would guess +/- 15% at concentrations as high as these is not great. There are environmental testing labs that can report ppt levels of PFAS now.