I know this has been done before but I can't find a definitive answer, maybe there isn't one!   What is the best oil for a 2018 VRS 230? The manual doesn't help by talking about 504, 502 or 508 but not specifying which one for which engine!   Castrol's website recommends 5W-40 but I've also seen lots of people talking up Quantum Longlife III 5W-30 as being what the dealers use.