[Opie]

Drive it until there is a problem....why stress over this if you are following proper oil change intervals?

I recently bought an older Subaru from a guy that did religious Blackstone Oil reports with every oil change...he sold it to me dirt cheap because one Blackstone report showed a high level of copper & lead, and he thought he heard a low knocking sound at startup, thought for sure motor was going out.

Noise turned out to be a worn out timing belt tensioner, report difference turned out to be a change only due to using a different motor oil than he had been for that one report. Report I did just to check came back fine....car runs great.