'Pennzoil with their wax based oil'

[Drew99GT]

I've personally taken apart two engines, both turbo Mitsubishi 4 cylinders, that were only run on Mobil 1 10w-30 for the periods that I owned the cars, and both had 100% no varnish at all inside, NONE. I've helped many a friend take apart high performance 4 cylinder engines, Honda and Mitsubishi, that were run with 3,000 mile mobil 1 oil changes, and they to did not have any varnish inside whatsoever, just shiny bright metal.

 

[BOBISTHEOILGUY]

In this link, I have a section about dewaxing that will help explain how it's done along with other parts of refinement.

http://www.bobistheoilguy.com/oilbasics/ppframe.htm