Hi,
The 2 oils will mix without any problem. I have run 5W-30 in my wifes Suburban for 16000 miles. The oil has spent a little time in the lower vis area and then come back to a 5W-30 at about 4000 miles. But, my wear particles were always low. I do not have a problem with the oil thinning, as long as it protects. Wear particles are an indication of protection.
Terry says it is PAO oir group 1V, The website says it is synthetic, and our chemist assures me it is.
So, I have to say it is. On the FAQ's it says,
"Motor Oil
Is Royal Purple® synthetic motor oil?
Yes. Royal Purple® Motor oils are composed of a proprietary formulation of synthetic base oils and synthetic additives containing iso-paraffinic diluents."
So, other than you asking a lab to identify the base oils when you do a VOA, that is what I am going with.
I tust this helps.
Llew