Originally Posted By: ewgoforth
Do you know who does the NAPA testing? The picture on their site sure looked like a Blackstone kit.
IIRC it goes to a Polaris lab.
Some have issues with Blackstone, others dislike Polaris; for different and various things.
I choose not to use Polaris, I don't like they're report structure, they classify some additives as 'contaminants' and to me don't provide the same level of personal care or interpretation.
I choose Blackstone knowing they charge more than Napa/Polaris for testing and TBN, that their fuel analysis is interpolation not measured, etc., etc. I just like them better.