New-to-me Subaru, what oil to go with?

Joined
Apr 18, 2005
Messages
2,259
Location
Easton, PA
So I finally bit the bullet and wound up getting the old lady a new car to replace her soup ca-- I mean Dodge Caliber. Got a 1-owner 2012 Subaru Outback 2.5i with 165k miles on it. The Carfax was extensive and thorough with dealership service its whole life and about a year ago it had the head gasket, radiator, and thermostat done (which I know is a chronic Subaru issue). I know it calls for 5w30 however I'm looking to get ahead of any oil burning or overheating issues.
I've always been a Castrol man (Though I currently run PUP because of my HEMI still within warranty) but I'd like to run a thicker oil, of any brand really, for a couple reasons. I don't feel 100% comfortable running an Xw-40 weight but any 0/5w-30 is on the table.
1. Her daily commute is 140 miles round trip 1/3 interstate and 2/3 rural hilly state highways so lots of higher RPM and varying load due to the elevation changes. 2. Given the age/mileage there's enough chance of regular wear that having a little extra viscosity may aid in offsetting any changes to tolerance (The car does pass a compression test). and 3. She isn't great about telling me when she hits the mileage for an oil change so to offset fuel dilution.
Going with a full synthetic because we have inordinately harsh winters and I'll probably be throwing a Napa Gold on for filter.
Any suggestions, solutions, tricks, or other information as to what to go with is much appreciated.
There is nothing "chronic" about hg's & overheating. If the original's lasted well past 100k then that isn't abnormal at all and once done with newer MLS gaskets it's a moot point. I would be more concerned if the rear & front diff fluids were never changed as well as the transmission(CVT). There is no fuel dilution issue either as they are still multiport injected, direct injection didn't happen till very recent. The only difference would be the newer engine is a timing chain vs. belt and has a top mounted oil filter.

If chain I'd use something along the lines of a HM 5w30 Syn, something that can take a beating from the chain. If not any 5w30 would be fine in synthetic.
 
Joined
Aug 20, 2003
Messages
18,397
Location
NE,Ohio
Early subaru CVT + EJ series engine is not the best combo

I'd run a 0w40 or 5w40 in it. or at least a "thick" 5w30 such as pennzoil euro L
The EJ series is an old design that got modern addons it does very well on thicker oil.

Make sure the CVT and differentials have fresh fluids.

Just out of curiosity, why would a broken ground strap cause the head gasket to blow? My BiL has a Subbie.
Excessive current grounding through HG vs ground strap. Can cause deterioration.
 

OptOut

Thread starter
Joined
Aug 7, 2016
Messages
103
Location
New Hampshire
There is nothing "chronic" about hg's & overheating. If the original's lasted well past 100k then that isn't abnormal at all and once done with newer MLS gaskets it's a moot point. I would be more concerned if the rear & front diff fluids were never changed as well as the transmission(CVT). There is no fuel dilution issue either as they are still multiport injected, direct injection didn't happen till very recent. The only difference would be the newer engine is a timing chain vs. belt and has a top mounted oil filter.

If chain I'd use something along the lines of a HM 5w30 Syn, something that can take a beating from the chain. If not any 5w30 would be fine in synthetic.
We're still waiting for the vehicle to be delivered but when I looked at it the oil filter was underneath and I'm relatively certain its a chain driven motor
 
Joined
Apr 18, 2005
Messages
2,259
Location
Easton, PA
We're still waiting for the vehicle to be delivered but when I looked at it the oil filter was underneath and I'm relatively certain its a chain driven motor
If the oil filter is underneath it is a timing belt motor. EJ25=belt FB25=chain. Look for that on the top to left of the alternator.
 
Joined
Oct 6, 2020
Messages
253
Oil filter on bottom and plastic timing cover=ej series sohc engine

Oil filter on top and aluminum timing cover=fb engine.

You have a n/a ej series engine. Been running sohc ej series in NH for the past 7 years, with mileage twice as much as yours. You need nothing more than a 5-30 synth and 7317 oil filter.

Only thing that worries me about your entire message is the words "dealer head gasket replacement".

Check pcv and hoses going from valve covers to intake.

Subaru, hills, on/off throttle=check oil regularly.
 
Joined
Oct 6, 2020
Messages
253
Because this engine uses 2 VVT (one on each head) solenoids the old 10mm EJ oil pump they have used forever isn't quite up to the job. They set the low oil pressure warning light at 2.5 psi and they can real close to that 3-5 psi at hot idle on 5w30 even when new, it is just enough to keep it alive.
I have done 3 of these engines since last year, all are running the 11mm pump and maintain 25-28 psi hot idle and at 3K rpm about 65 psi, all run either Mobil 1 ESP 5w30 or Mobil 1 0w40 Euro oil, it helps the stock pumps a lot and works perfectly fine in NE winters.
It will give the stock 10mm pump engine 8-10 psi hot idle and 50 psi at 3K rpm which is much better than an API 5w30. OE, Mazda RX or Wix filters are fine.

One of the causes for HG failure is broken ground straps from the head to the frame, check them when you do an oil change and replace them with heavier ones if broken. These cars are also known for ghost walking in snow and going right through stop signs in the snow even with dedicated snow tires, look into it or post the question.

This is under the car attached to each cyl head.

View attachment 111085
Nothing wrong with your statement.....except this gentleman, according to his description uses a ej series engine.

The ground strap on each head is a great piece of info applicable to Subarus regardless of engine code.
 
Joined
Nov 29, 2021
Messages
3,870
Just out of curiosity, why would a broken ground strap cause the head gasket to blow? My BiL has a Subbie.
Electrolysis. It creates corrosive coolant. https://allwheeldriveauto.com/subaru-head-gasket-problems-explained/

It's a well-known Subaru EJ series (but not EZ 6-cylinder) engine problem.

The health of the electrical system is a contributing factor. We know that corrosive coolant is part of the problem, we know that electrolysis is a result of increased voltage levels in the cooling system as a result of poor grounding , we know that a poor ground can be caused by resistance in the primary electrical circuit. We know the coolant is the same in the entire engine, and the gaskets the same left to right the only difference is the fact that the ground is at the left side of the engine and that if there is voltage present in the cooling system it will always travel the shortest path to ground and the ground is on the same side of the engine as the gasket that always fails the most via external coolant leaks.
 
Joined
Nov 20, 2006
Messages
28,644
Location
MA, Mittelfranken.de
Nothing wrong with your statement.....except this gentleman, according to his description uses a ej series engine.

The ground strap on each head is a great piece of info applicable to Subarus regardless of engine code.
My post addresses the EJ engine not the FB. A 2012 outback US spec should be a EJ253 with a 5EAT or 6 speed manual.
 
Last edited:
Joined
Jul 16, 2022
Messages
103
So I finally bit the bullet and wound up getting the old lady a new car to replace her soup ca-- I mean Dodge Caliber. Got a 1-owner 2012 Subaru Outback 2.5i with 165k miles on it. The Carfax was extensive and thorough with dealership service its whole life and about a year ago it had the head gasket, radiator, and thermostat done (which I know is a chronic Subaru issue). I know it calls for 5w30 however I'm looking to get ahead of any oil burning or overheating issues.
I've always been a Castrol man (Though I currently run PUP because of my HEMI still within warranty) but I'd like to run a thicker oil, of any brand really, for a couple reasons. I don't feel 100% comfortable running an Xw-40 weight but any 0/5w-30 is on the table.
1. Her daily commute is 140 miles round trip 1/3 interstate and 2/3 rural hilly state highways so lots of higher RPM and varying load due to the elevation changes. 2. Given the age/mileage there's enough chance of regular wear that having a little extra viscosity may aid in offsetting any changes to tolerance (The car does pass a compression test). and 3. She isn't great about telling me when she hits the mileage for an oil change so to offset fuel dilution.
Going with a full synthetic because we have inordinately harsh winters and I'll probably be throwing a Napa Gold on for filter.
Any suggestions, solutions, tricks, or other information as to what to go with is much appreciated.
mobil 1 5w-30 EP (HM is available) and fram ultra. Change every 5k to 'get ahead' of oil burning.

 
Joined
Nov 20, 2006
Messages
28,644
Location
MA, Mittelfranken.de
Oil filter on bottom and plastic timing cover=ej series sohc engine

Oil filter on top and aluminum timing cover=fb engine.

You have a n/a ej series engine. Been running sohc ej series in NH for the past 7 years, with mileage twice as much as yours. You need nothing more than a 5-30 synth and 7317 oil filter.

Only thing that worries me about your entire message is the words "dealer head gasket replacement".

Check pcv and hoses going from valve covers to intake.

Subaru, hills, on/off throttle=check oil regularly.
What EJ? It would be a unicorn for an open deck EJ to go much more than half that without some HG issues, high mile closed deck are very common.
 
Joined
Oct 6, 2020
Messages
253
What EJ? It would be a unicorn for an open deck EJ to go much more than half that without some HG issues, high mile closed deck are very common.
Sorry bud.
What EJ? It would be a unicorn for an open deck EJ to go much more than half that without some HG issues, high mile closed deck are very common.
You're completely correct. I read your post and didn't read the parentheses. (One on each head) .

My post reply was on 5-30. That's what I run on my soch n/a Subaru. Didn't mean I ran original head gaskets that long. Any man that did that needs to buy a lottery ticket.

On the "gaskets done at the dealer" is my biggest concern. If you only knew the process. I seen guys take heads off, whiz wheel both block and heads, torque to **** near 90 lf/lbs.

Once again, you are correct. I read your reply too quick. My apologies.
 
Joined
Aug 20, 2003
Messages
18,397
Location
NE,Ohio
No problem, it happens to me all the time. Replaced HG can be a very sketchy fix on these depending on who did it, if it was done in the car the chances of it being a long term repair are pretty slim.
IIRC in 2012 the 4cyl got a 6mt or cvt and the 6cyl got the 5speed. The 2013 got the fb25 and I know that had the cvt.. not positive about 2012..

I owned 2011,2015 foresters and did all the maintenance on a 2013 outback so I am fairly familiar with that time frame.
 
Joined
May 15, 2012
Messages
4,401
Location
The land of USA-made Subies!
Never hear of overheating issues other than ancient early, EJ motors. Get yourself a cup wrench that fits your filter choice. since the Filter is surrounded by the exhaust heat shields with just a "hole" to drop the filter out. At least it was this way on our '09.

That EJ engine design is truly easy on oil, Dry timing system, NO tappets, rollercam, jam nut valve lash.

I bet the Quaker State full synthetic 10W30 I am using currently on my Ford would do well in the Subaru. It would avoid the gum and varnish of a 5w30 and it has a minus 54 degrees pour point.

I would do a turkey baster Powersteering fluid change if the Outback still has Subaru excellent hydraulic steering.

I am in NH also, just 15 miles over the Haverhill. MA border. - Ken
The non-turbo EJs will happily run any xW-30 from now until the end of time. I will probably even run a thicker 20 weight in my car this winter, just for the hockey sticks of it. The EJ257s most times like thicker oils due to the overheating condition of the driver rear cylinder. I experimented over the years with xW40s in my non-turbo EJs and all I ever really noticed was the car went ~25 miles fewer to a tank compared to the 30s. Sure, the UOAs tended to be just ever so slightly "better" but I'm not going to ever see an EJ fail because of a spec oil. I've had 5 EJ25s, with every single one making it between 160k (still in use)-234k(sold & still running) with no known rebuilds and loving the cheap SN 30 weights. Agree on your other maintenance tips, the PS trick lets you slowly change the total volume with minimal work. The "lifetime" filter that came on older cars with 4EATs was another phenomenally easy task to change!
 
Joined
Oct 6, 2020
Messages
253
The non-turbo EJs will happily run any xW-30 from now until the end of time. I will probably even run a thicker 20 weight in my car this winter, just for the hockey sticks of it. The EJ257s most times like thicker oils due to the overheating condition of the driver rear cylinder. I experimented over the years with xW40s in my non-turbo EJs and all I ever really noticed was the car went ~25 miles fewer to a tank compared to the 30s. Sure, the UOAs tended to be just ever so slightly "better" but I'm not going to ever see an EJ fail because of a spec oil. I've had 5 EJ25s, with every single one making it between 160k (still in use)-234k(sold & still running) with no known rebuilds and loving the cheap SN 30 weights. Agree on your other maintenance tips, the PS trick lets you slowly change the total volume with minimal work. The "lifetime" filter that came on older cars with 4EATs was another phenomenally easy task to change!
I totally agree with the 5-30.

BTW, if you're still having issues with the driver's side overheating on the 257, take out the plug out the passenger side head and t that into the heater core return just like the jap/euro 257s cone factory with.
 

Rex

Joined
Oct 2, 2005
Messages
112
Location
Indiana
I ran our 2011 Outback 2.5l running Walmart 5W 30 HM Super Tech motor oil out to 10K OCI. Added the Schaeffer Moly EP oil treatment and had it for 235,000 until I traded it in on another Subi.
 
Last edited:
Joined
Nov 29, 2021
Messages
3,870
What EJ? It would be a unicorn for an open deck EJ to go much more than half that without some HG issues, high mile closed deck are very common.
No problem, it happens to me all the time. Replaced HG can be a very sketchy fix on these depending on who did it, if it was done in the car the chances of it being a long term repair are pretty slim.
Ahhh. Thanks!
Yeah, the EJ255/257 "Turbo gaskets" are supposed to be the "permanent fix." I think you mentioned it can be any MLS gasket, has to be prepped correctly. The EJ gaskets de-laminate, weep, them blow. I actually have replacement bolts to go with 255 gaskets, we'll get there.

Subaru 4EAT transes have wonderful external oil filters, too. Truly minimal work of jack up one side for ease, loosen, remove, catch fluid, paper towel, reinstall, refill to proper level. I could link the gaskets but it is fairly easy to find EJ255/EJ257 Turbo Gaskets. Six Star is the other one. After careful consideration, I chose Subaru OE 255/257.

I need to re-read your post advocating for 0W-40 for stock EJ oil system, but you may be on to something.

I've owned EJ car and EZ H6-3.0 car. There is a lot of debate on which is better.. long-term, I feel the H6 simply has less problems in almost every single way, that's 4EAT trans too, but I will leave that there.

Keep the grounds clean and coolant fresh to minimize chance of gasketing issues and also buy $230 Subaru Master Engine Re-seal gasketing kit, take out and THROW AWAY the Head Gaskets that come with that kit, replace with 255/257 or Six Star for when it is all apart.
 

KJH

Joined
Oct 15, 2011
Messages
133
Probably not right now at $67 for 5 quarts. I was going to pick some up for my BMW at Walmart yesterday, but they had Mobil 1 0w-40 for $24.47 for 5 quarts.

I cry remembering that Castrol 0w-40 was on sale for $21/5quart at my local supermarket chain for a couple months fall of last year and was always well stocked.
 
Top