Some of the best UOAs for the Subaru 2.5L (EJ 255) turbo engine are found in Rotella T6 5w-40 (SM) and GC 0w-30 (SL). There is almost a cult following.
But now, effective mid-2011, Subaru states that a 5w-30 SM+/GF4+ energy conserving or resource conserving synthetic oil is the REQUIRED oil. There is no wiggle room. So, for warranty purposes it's goodbye RT6 and GC, even though the EJ 255 motor hasn't changed since 2006 and those oils have an excellent track record in this application.
Here's the question: which oil meets the required specifications, but most closely mirrors the positive attributes of RT6/GC? It has been said that the EJ 255 is hard on oil, shears it quickly, and suffers from the occasional spun bearing when the oil gets too thin under demanding (hot) conditions. Accepting these premises as true for sake of argument, which 5w-30 SM+ EC synthetic is optimal?
Thanks,
Dave
PS - First post!
PPS - I know this general topic has been discussed many times over on NASIOC, but no one has posed this exact question before.
But now, effective mid-2011, Subaru states that a 5w-30 SM+/GF4+ energy conserving or resource conserving synthetic oil is the REQUIRED oil. There is no wiggle room. So, for warranty purposes it's goodbye RT6 and GC, even though the EJ 255 motor hasn't changed since 2006 and those oils have an excellent track record in this application.
Here's the question: which oil meets the required specifications, but most closely mirrors the positive attributes of RT6/GC? It has been said that the EJ 255 is hard on oil, shears it quickly, and suffers from the occasional spun bearing when the oil gets too thin under demanding (hot) conditions. Accepting these premises as true for sake of argument, which 5w-30 SM+ EC synthetic is optimal?
Thanks,
Dave
PS - First post!
PPS - I know this general topic has been discussed many times over on NASIOC, but no one has posed this exact question before.
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