No need fully synthetic engine oil for your Proton Persona.. Liquy Moly MOS2 already good enough even for my previous dugong.. did tried all kind of fully synthetic oil, still Liquy Moly MOS2 better then most of it.. maybe some actually better but its just too expensive (which cost rm200+ only for engine oil)

The most important is consistently change engine oil at right time or mileage whichever come first.. not by using very expensive engine oil and forgot to change it past the due date or mileage..