I had a 2014 Subaru Forester 2.5L CVT that I let my son-in-law have when he totaled his Honda Pilot. I drove it from new to about 45K and it never used any measurable oil in 7500 OCI, using M1 0w-20, or Castrol 0w-20 Synthetic. After having his local Subaru dealer change the oil, invoice says they used Mobil 0w-20, it seems to use some oil, especially on extended drives on the Interstate. Doesn't seem to use any with local driving. Recently I did an oil and filter change on the 14 Forester and used Valvoline full synthetic maxlife 0w-20 and he checked the oil weekly for several weeks and no usage. Then he took a trip on the Interstate for about 500 miles round trip, and when he returned the oil level was down about 1/4 quart below the full mark( based on his measurements). I had set it about 1/4 quart above the full mark when I changed it. The 14 Forester now has about 65K on it.
So, I recently found a UK 2017 FB-2.5L Forester owners manual, and it indicates that it comes from the factory with 0w-20 Synthetic oil, but 5w-30 or 5w-40 can be used, not just to top off, but as a regular replacement oil. No such statement in the US manual for this vehicle(CAFE?), but I am very tempted to switch to a 5w-30 next oil change, or maybe mobil 1 0w-40. Under high-speed driving does it seem reasonable to believe that either of these oils might help reduce oil consumption under these conditions?
So, I recently found a UK 2017 FB-2.5L Forester owners manual, and it indicates that it comes from the factory with 0w-20 Synthetic oil, but 5w-30 or 5w-40 can be used, not just to top off, but as a regular replacement oil. No such statement in the US manual for this vehicle(CAFE?), but I am very tempted to switch to a 5w-30 next oil change, or maybe mobil 1 0w-40. Under high-speed driving does it seem reasonable to believe that either of these oils might help reduce oil consumption under these conditions?