As you can see from the PQIA data, there has been a change in Royal Purple's formula.
One version is the high sodium version similar to Valvoline Synpower and the other (newer version, I think) is a high Boron formula with moly. (which seems to be a better formula, IMO.)
Does anybody know when this change happened?
Does anybody know how to read the date code on Royal Purple bottles?
I ask because I picked up several bottles of 10w30 on 'Clearance' at AA.
I would prefer not to mix the high sodium (no moly or boron) formula with the moly/boron (no sodium) formula.