Molakule,
You are right. It is the PAO/Ester mix with the "Propretary" additives. Just how much of each, is up to the Chemist, and the carrier oil is used for the Additives.
OUTRUN. Because someone asks for the % of each, does not mean RP has to comply. Many years of experimentation,testing,and reformulation, have gone into it, and to give out this information would be stupid. We are in a market that measures it profit on quarts in cents.
If there is a problem with the RP 21 or the 5W-30, send it to RP and a lab of your own choice. You can see if RP is full of it, and how they respond to your needs. But to get upset because they do not want to give %, is silly. You are the consumer, and you vote with your pocket book. If it does not make the grade, do not buy it.