2014 Subaru Forester 6MT 2.5L NA
ODO: 78,420
Estimated hours on oil: 64
Miles on oil: 2,625
Out: 5.5qt of mix (7 parts Delvac 1300 15w-40 + 3 parts Mobil 1 EPHM 5w-20) + 2 pt rislone high mileage concentrate
In: 1 pt rislone high mileage concentrate + 5qt Mobil 1 0w-40 Euro
Off: XG7317
Estimated hours on filter: 84 +64 = 148
Miles on filter: 3,195 + 2,625 = 5820
On: XG7317
For the trailing oil: car consumed 1 pt, replaced with rislone 4102. Did not show signs of consumption for the next ~380 miles. Consumption seemed to slowly return after commuting to and from work; added 1 pt of 70:30 Delvac:M1EPHM mix. Consumption continued at same pace; replaced 1 pt with rislone 4102 for last 80 miles (ODO 78,340) for more severe final cleaning. Changed at Walmart Auto.
From what I can tell, I don't see oil leaking, and the tube connecting the PCV valve to the intake manifold has some oil in it. (no oil around PCV valve threads, no pooling on engine; oil only in the tube.) I suspect stuck compression rings due to either varnish or carbon. Looking to install a catch can on this OCI. I am not sure how well the PCV baffling is, but this should help keep oil from being sprayed into the cylinder. Most people's remedies on subaruforester(dot)org involve thicker oil (either additional oil cooling or M1 0w-40 euro) to cut consumption rate in half, but no one has tried PCV replacement or the catch can. I have already cleaned the PCV valve last time, so I don't suspect that. Also added Gumout AIO fuel cleaner in gas this time for elevated PEA.
Despite this, the optimism for restabilizing a low consumption rate (1pt-1qt in 10km) is not strong.
