Dad2leia writes:
"I was looking for compatibility issues since they say that it is an extreme pressure additive, and most oils, if not all from what I've read and learned have no extreme pressure additive package in them to begin with."
Not true. ZDDP is a very common extreme pressure anti-wear additive/anti-oxidant found in most common automotive lubricating oils. If you prefer, you can go to BLOBITOG and read what the talkers that talk about oil all day long say about it, or go here:
http://www.lubrizol.com/LubeTheory/prop.aspand read what the people who DESIGN AND MANUFACTURE OIL ADDITIVES FOR A LIVING all day long say about it. Your choice.
The Chevron site (Chevron Oronite division designs and manufactures oil additives too) has some good info also.
http://chevron.com/PRODUCTS/oronite/ Expect some fairly technical accurate articles rather than the, "I heard that. . . . , My friend said that. . . . , My dad said that . . . . , My mechanic told me that . . . . blah, blah, blah, type discussion so popular elsewhere on the net.
Chumley