If you check out the NC Procurement post here, it appears that Chevron Supreme Synthetic is a PAO. In comparison, some Royal Purple and Amsoil oils are listed as being Group III (the Amsoil XL7500, I believe that it is called). Personally, I have never been able to find Chevron Supreme Synthetic 5W-30 oil. I can find only the Chevron Supreme Synthetic 10W-30. I was going to use Chevron 5W-30 synthetic in my car but could not find it (I was going to use it because Chevron Supreme conventional did so well). At the checker Auto Parts Store where I can find Chevron Supreme Synthetic 10W-30, it sells for about $3.00 a quart. If this Chevron synthetic oil is really a PAO, then here is a PAO oil selling for close to $2.00 less a quart then Mobil 1.