hi! as long as the oil is multigrade (like 20W-50 etc), it will not make any significant difference (sa pagkakaalam ko ). follow your car manual's recommended viscosity and periodic maintenance and everything will be fine. in my opinion, old autos should be oil changed earlier i.e. 3-4 months or 3000km whichever comes first (standard is 5000km or 5months).
Bale ang gamit ko ngaun is Castrol GTX 20W-50 dahil sa init ng panahon natin at ng makina ng MPV sa ngaun ok naman sya sa oil. hopefully ok sya talaga, ok po ba ang royal purple? baka hindi sya suitable sa old auto like mine.