ABOUT SUBARU EJ20 TURBO MOTOR FOR SALE

My problem is, how does Pennzoil stack up when it comes to top quality? Iv been jogging 10W-30W semi-synthetic for a couple of years now and havnt had any challenges but would love to know very well what you fellas Assume. I could change to Royal Purple because its conveniently obtainable here but would it be an improvement?Good responsive support