I'm going to search around too looking for the thread regarding RP & MB1.
**Pennsylvania grade crude oil is especially important because of its inherent superior lubricating qualities.
-A year or two ago I read on here about how clean and how protective the the Pennzoil Ultra works inside of newer engines. Seems as though, the big name oil companies of great quality each are a bit different and eccell at different aspects of engine protection.
*Question- Pennsylvania sweet paraffinic oils make high quality lubricating oils for conventional oil blends, qualities and is free of asphalt constituents, contains only trace amounts of sulfur and nitrogen, high ZDDP, . crude into the mix when using their synthetics, right? Pennzoil synthetis Ulta claims a clean engine. Protection, I don't know about though..
ME, I LIKE Mobil1, Amsoil, and Royal Purple a little bit.