I have been getting PDS for Supertech All Mileage oils from Highline Warren and in the 5w30 version CAS#64742-58-1 is 65-85% of its makeup compared to a PDS I got not long ago for 10w40 and its top CAS#64742-54-7 is at 45-70%. This CAS is from my understanding grp.3. Correct me if I am wrong but what I was able to find out is that 64742-58-1is basically (spent) recycled oil. If this is the case then WH may be getting less if any of the high performing grp. 2 from Exxon Mobil as they once did. While there may not be anything wrong with recycled oil,is it as good as the XOM they may no longer be using. As others and myself have wondered, is ST being made cheaper.