Synthetic oil change-over

Mobil Super
What’s the difference between Mobil 1™ and Mobil Super™ Synthetic motor oils?
Mobil 1 is part of our ultimate line of advanced full synthetic oils. It uses the latest in additive and base oil technologies that provide superior protection

Question:
Have Group 3 Base Oils Been Substituted for Better PAO Base Oils?
Why does Mobil 1 refuse to specify as to the base oil used in their synthetic products. I remember the Mobil 1 oils in the past proudly proclaimed that it was a PAO based oil. We all know the newer group 3 hydrocracked base oils are much cheaper to use than PAO based oils and are less stable in high temps. It would seem to me that if Mobil 1 still uses the better PAO base oils as their primary base oil, you would want to clarify it among those who are switching to other oils because of the ongoing internet talk that says Mobil has substituted group 3 oils for the better PAO oils. Any comments that would clarify the issue?
-- Wayne Swicegood, Asheboro, NC
Answer:
As we're sure you can understand, ExxonMobil does not discuss formulations publicly,as this information is proprietary. We would rather focus on the advanced technology and proven performance that our engine oils and other products offer to our customers. Mobil 1 is the world’s leading synthetic motor oil and the one chosen by more original equipment manufacturers around the world as factory fill. We want those facts to speak for us so our customers feel confident they are getting a high quality, high performance product that provides ultimate protection to their vehicles.