There seems to be a question as to whether a problem would be created by changing from a Parafin base oil to a Petroleum Base oil? Or vice Versa? Any of you testers and mechanical gurus had any evidence which would affirm one way or another?
Not sure what you are asking. If I may make an assumption, it sounds like a bit of an "old school" question.
Here's some words/terms to look-up/learn:
paraffin(ic)- does not mean always "wax" in organic chemistry terms, more specifically in oil speak - really just means longer chain saturated alkanes. Any petroleum oil is mix of all sorts of these hydrocarbons.
napthene(ic) - basically ringed organic compounds, such as benzene
Base Oil groups I-V (and now VI!)- covered elsewhere in detail.
It's also worth learning about synthetic oil, to better understand the terms and gain a better handle on the knowledge
dene57K, as I tried to point out in that other ("Valvoline or Castrol?") thread, parrafinic bases ARE petroleum bases.
You might want to read up on Bob's site and not just this forum and you'll be better able to sort out your terminology.
It's no big, people come to this form with various pre-conceived notions and myths. Just search around (using the search feature) as most of the basics have already been discussed in numerous threads.
--- Bror Jace