In late 2021 I obtained a 114k 2013 Subaru Outback from the somewhat infamous first batch of possible oil burners/leakers. Obviously being 8 years old and of unknown provenance (besides Carfax saying it mainly lived in Florida, and being of clean title) I had no clue what oil changes, maintenance, etc. was done, nor did I know if it had had the shortblock replaced under warranty like the really bad oil guzzlers did.
I started it on 5W20 Valvoline Full Synthetic and it turned the 0.8 liter low oil light on at 3000mi multiple times. After 14k of this (two loads) I switched to 5W20 Castrol Edge which did the 0.8 liter low in 3900mi twice.
About this time in the story I come back around here and find out about the No VII oil from HPL and decide to add a Baxter anti-drainback valve (FB engines start with empty oil filter and galleries without it) which also switches to a M22 threaded taller filter. A full load of HP 5W20 EURO No VII and a Fram Ultra XG10575 were all added along with a replacement of all factory PCV parts so that I can rule out/eliminate oil consumption there. Also added a small cyclone catch can in line with the PCV valve so I can get the last bit and also see how much oil tries to come into the intake manifold.
I had read some of the threads about “cleaning” oil control rings with this oil and that’s why I switched to it, since the FB25 has small low tension ones. I was planning to run this first filter for 2000mi then cutting it open and checking for deposits, but to my surprise - 1100mi in, the 0.8 liter low oil light is on! I took the underpanels off and inspected to make sure that there weren’t leaks or other signs of where the oil has gone, and there are none. I was even wondering if the “cleaning” would reveal RTV leaks which these are known for, but so far there aren’t any. The cyclone catch can in PCV stream gathered just trace residue, probably less than 0.5 ounce.
Other than the disappearing of the oil it ran great and seems to be getting marginally better fuel economy with less tip in knock than before.
Cliff notes - first 1100mi with EURO No VII in the same grade as Valvoline and Castrol has 3x the oil consumption/disappearance
Thoughts? Is there some way that “cleaning” temporarily changes oil consumption in a way like this? Since I’m out of top off bottles of HPL and need to order more since I’ve used the whole 6 quart box, should I still buy 5W20 or go to a 30? Was this whole thing a bad idea?
How did I turn a non-consuming FB25 into a guzzler? Will it stop?
What am I missing?
(I am reaching out to David already)
I started it on 5W20 Valvoline Full Synthetic and it turned the 0.8 liter low oil light on at 3000mi multiple times. After 14k of this (two loads) I switched to 5W20 Castrol Edge which did the 0.8 liter low in 3900mi twice.
About this time in the story I come back around here and find out about the No VII oil from HPL and decide to add a Baxter anti-drainback valve (FB engines start with empty oil filter and galleries without it) which also switches to a M22 threaded taller filter. A full load of HP 5W20 EURO No VII and a Fram Ultra XG10575 were all added along with a replacement of all factory PCV parts so that I can rule out/eliminate oil consumption there. Also added a small cyclone catch can in line with the PCV valve so I can get the last bit and also see how much oil tries to come into the intake manifold.
I had read some of the threads about “cleaning” oil control rings with this oil and that’s why I switched to it, since the FB25 has small low tension ones. I was planning to run this first filter for 2000mi then cutting it open and checking for deposits, but to my surprise - 1100mi in, the 0.8 liter low oil light is on! I took the underpanels off and inspected to make sure that there weren’t leaks or other signs of where the oil has gone, and there are none. I was even wondering if the “cleaning” would reveal RTV leaks which these are known for, but so far there aren’t any. The cyclone catch can in PCV stream gathered just trace residue, probably less than 0.5 ounce.
Other than the disappearing of the oil it ran great and seems to be getting marginally better fuel economy with less tip in knock than before.
Cliff notes - first 1100mi with EURO No VII in the same grade as Valvoline and Castrol has 3x the oil consumption/disappearance
Thoughts? Is there some way that “cleaning” temporarily changes oil consumption in a way like this? Since I’m out of top off bottles of HPL and need to order more since I’ve used the whole 6 quart box, should I still buy 5W20 or go to a 30? Was this whole thing a bad idea?
How did I turn a non-consuming FB25 into a guzzler? Will it stop?
What am I missing?
(I am reaching out to David already)
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