RLI BioSyn SHP 5w-40 HD, 5000 mi, 1996 BMW M3

[d00df00d]

The new report has been uploaded. For anyone who has seen and passed judgment on the old one, please see the new, unfortunately higher but significantly more sensible numbers for oxidation, nitration, and sulfate by-products.

 

[benjamming]

Oxidation doubled in this re-test didn't it? What does that say about lab confidence? So, which set of data is correct - old or new?

 

[d00df00d]

Originally Posted By: benjamming
Oxidation doubled in this re-test didn't it?

The old number was a lot lower than what even the virgin oil should have shown. The new number is in the correct range. So, yes, the number did double, as it should have.

Same thing with the sulfate by-products.


Originally Posted By: benjamming
What does that say about lab confidence?

All labs make mistakes; it's just a matter of how likely those mistakes are and what they do about it.

All I can say here is that I'm glad I'm getting Dyson's Premium service. Without his interpretation and the subsequent conversations, these errors probably wouldn't have been caught.


Originally Posted By: benjamming
So, which set of data is correct - old or new?

I think the new oxidation, nitration, and sulfate by-products numbers are more reliable.

 

[d00df00d]

So, here's something new: I just discovered that the duct between the MAF and the throttle body had all sorts of radial cracks in it. The hose leading from it to the IACV was getting there, too. I have no idea how long it has been like that, but I can't imagine it didn't affect the fuel dilution number. I know the car has had a slight stumble at WOT above 5k RPM for several months now, and recently developed some hesitation at startup; now that I've replaced those pieces, those problems are gone.

Boy, do I feel silly for not catching that earlier. Here's hoping the fuel number goes down significantly on the next UOA.