Originally Posted By: Cooper
Running conventional is not an option! Read your manual! You have to run synthetic 0w20. You can pick any major brand. Buy OEM filters or Wix 57055 for the correct PSI rating.
SUBARU specs synthetic so they can market an "extended" OCI, and claim "LOWER" maintenance costs... however, it seems that SOMETHING has made them reconsider...! ( fuel dilution, and oil consumption are issues...)
SUBARU specs 0w20 purely for fuel economy, with "adequate... maybe..." durability. My 2011 Impreza specs 5w30, or if warmer 10w40 , and if heavy duty use... ? even 20w50. Yes, i understand this is the last gen. engine, but it is only very recently that manufacturers have stopped listing various grades for diff. temps.
SUBARU specs a higher oil filter by-pass pressure to protect the turbo from too much "by-passed" oil, and possible contaminants etc...and turbo failure... note: TURBO engines...
So... run a conventional if you want, just keep the intervals reasonable, but 5000 miles should be just fine given the driving conditions. Or use any brand name 20 grade synthetic, but watch the intervals...or use a 30 grade for a little safety net in case of oil thinning thru fuel dilution...
Your engine won't care if the oil is synthetic, conventional, 20/30/40 grade, brand name or anything else... as long as it is reasonably fresh.
Your engine will care if you extend the OCI too far out without being sure the oil is holding up. Under warranty, stick to manufacturer specs AT MINIMUM! for OCI.