Thinking about switching to Royal Purple SAE 5W-40 High Performance Synthetic Motor Oil for my next oil change. They have a 0w-40 but it does not have the Synerlec additive. The 5W-40 does. They also have the HPS oil in 10w-40 with the zinc / phosphorus package.
Pros / cons?
https://royalpurpledirect.com/royal-...tic-motor-oil/