Originally Posted By: Eddie
The NAPA site doesn't say what is covered with their analysis. Anyone? Ed
I don't have results from my own yet, but from what I've seen you get wear metals, additives, contaminants and TBN. No oxidation, sulfation, nitration nor TAN. I'm referring to a gasoline engine sample, of course. They also test diesels, transmissions and diffs. With a transmission or diff, I believe they test TAN (no TBN required).
Polaris and Caterpillar labs test oxidation, sulfation and such in a standard test for decent price.