Two Subarus - common oil? HPL, intervals?

[MDN]

Hey all,

I generally don't post, just read, but here is my situation.

I have a 31k 'new' WRX - GDI, turbo, about 30% more cylinder pressure than stock (17psi boost). So far I have been giving it Motul X-Clean EFE+ 0W-30 or 5W-30 and factory filters every 3k miles. It is my first GDI engine and I have not gotten into frequent enough oil testing to determine how long it takes for fuel dilution to come up in this engine, so stayed with the classic 3k interval. It has no noticeable consumption, very happy car.

I also have a 2013 Outback with the NA PFI 2.5 liter version of the same engine. To make a long story short, it is in the midst of a total engine refresh, new rings, machine work, and all. It used to be a pretty good oil consumer and spent most of its late life on Valvoline Advanced FS 5W-20 SP. (I found all the oil control rings full of crud of course though everything else was quite clean). I was comfortable with 5k intervals, also no oil testing to support.

edit for clarity: these are both the timing chain FA/FB variants, not EJ

I am thinking about making the oil common between these two, once I get the Outback broken in. Weather here is around -5f in the winter and 100f in the summer. I really like everything I have used from HPL, and the customer service too. I have already had a conversation with HPL Dave about this and have his recommendation (its Supercar).

I am also wondering if I do this, what is sensible about intervals for each. I try to keep my vehicles as "forever" as I can. As much as I see people running 10k intervals, I cannot wrap my mind around how much fuel is in that sump. But 3k on HPL starts to make me think I am crazy.

I am all ears for input on this, I have a week or two until I make my HPL order to break in the Outback.

Thanks!

 

[SubieRubyRoo]

Mobil 1 Full Synthetic 0W40 since it's on every WM shelf. If you've turned up the wick on your Rex there's no point in not going to a 40 grade, and EJs have always lived famously on 40 grade.

If you want to spend on HPL, feel free, but SuperCar in an NA EJ may be the zenith of irony, and that's coming from a guy who's owned 5 of them...

 

[MDN]

By "new" WRX I meant VB, with FA24

My 420 wheel EJ has been on 5W-40 Ravenol for years

 

[Brian123]

I have already had a conversation with HPL Dave about this and have his recommendation (its Supercar). I could also do the Motul I've already been running in the WRX. Or Mobil 1 ESP 0w30. Those are my contenders at this point.

It sounds like you had a conversation with HPL Dave who gave you fantastic advice, and you have doubts? I will say this; I have talked with HPL Dave on the phone and I would never start a thread and bring up that I had a conversation with him.

 

[MDN]

It sounds like you had a conversation with HPL Dave who gave you fantastic advice, and you have doubts? I will say this; I have talked with HPL Dave on the phone and I would never start a thread and bring up that I had a conversation with him.

Suppose I'm sold that I want to do HPL and am trying to figure out good intervals. Dave and I did not discuss intervals.

I believe I see your point, see how that could look bad. To be honest any time I get on this forum it takes any certainty I had/have about what I have learned from my cars over the years, and influences me to want to try new things. Hence ESP.

edited original thread start to reflect.

I would just do something in the 3-4k range if I was staying with over the counter oil like I have been. Then I see the fella tracking the VW wagon pushing 10k intervals with HPL. Blows my mind.

 

[SubieRubyRoo]

Suppose I'm sold that I want to do HPL and am trying to figure out good intervals. Dave and I did not discuss intervals.

I believe I see your point, see how that could look bad. To be honest any time I get on this forum it takes any certainty I had/have about what I have learned from my cars over the years, and influences me to want to try new things. Hence ESP.

edited original thread start to reflect.

I would just do something in the 3-4k range if I was staying with over the counter oil like I have been. Then I see the fella tracking the VW wagon pushing 10k intervals with HPL. Blows my mind.

Ah yes, been a long day. I thought you had 2012. Just last week I told somebody 2013 was the first year for the FB25 in Outbacks, and this is what I get for skimming... lol

 

[ka9mnx]

Dave and I did not discuss intervals.

You should have.

 

[altaylar]

Your timing chain is really good at chopping VII, but HPL is also very durable against it. I would not mind 10k interval HPL, or 5K interval Mobil 1 0w40 if this was my car.

 

[CleanSump]

Motul X-Clean EFE+ is a very good oil that has the toughest approvals. Have you considered taking it to 5k miles and then sending a sample to a lab that does reliable fuel dilution testing? Without testing for fuel dilution, you don't have anything to base a decision on.

 

[facility1]

If Motul oil is working for you, just use that, its a great oil,,or you may want to consider AMSOIL Signature Series 5w30 for a longer oci.

 

[Delta]

Your timing chain is really good at chopping VII, but HPL is also very durable against it. I would not mind 10k interval HPL, or 5K interval Mobil 1 0w40 if this was my car.

10K OCI on a tuned FA24? Yea no.

Unless the OP starts doing internal mods like forged rods and the such, 0/5w30 is fine. That's already bumping it up from the 0w20 it's spec'd with from factory.

 

[altaylar]

10K OCI on a tuned FA24? Yea no.

Unless the OP starts doing internal mods like forged rods and the such, 0/5w30 is fine. That's already bumping it up from the 0w20 it's spec'd with from factory.

I remember seeing a video on YouTube where David from HPL was testing their VII for mechanical shear, and that result seemed to easily durable enough for a 10k OCI, especially given we are talking about 1 to 2 grade higher already

 

[Hohn]

Mobil 1 Full Synthetic 0W40 since it's on every WM shelf. If you've turned up the wick on your Rex there's no point in not going to a 40 grade, and EJs have always lived famously on 40 grade.

If you want to spend on HPL, feel free, but SuperCar in an NA EJ may be the zenith of irony, and that's coming from a guy who's owned 5 of them...

This. Not a subaru guy, but Euro FS is so good and so universally applicable, it should be everyone's starting point for oils, deviating only as needed for particular application needs.

If you can find ESP X4, that's arguably better oil in some cases, but I've never seen it in any local store. And Supercar is basically the old ESP formula, so it's also going to be pretty dang good.

Really, any Mobil 1 0w40 is going to be a great choice if it's not the very rare C40 Gt blend.

 

[Hohn]

Suppose I'm sold that I want to do HPL and am trying to figure out good intervals. Dave and I did not discuss intervals.

I believe I see your point, see how that could look bad. To be honest any time I get on this forum it takes any certainty I had/have about what I have learned from my cars over the years, and influences me to want to try new things. Hence ESP.

edited original thread start to reflect.

I would just do something in the 3-4k range if I was staying with over the counter oil like I have been. Then I see the fella tracking the VW wagon pushing 10k intervals with HPL. Blows my mind.

Don't guess on interval. There's zero risk of going 5k initially on HPL if the engine's not a disaster right now.

Fill HPL. Send baseline sample. Sample again around 5k. Choose your interval based on the difference between baseline and 5k sample. It might be 8k, might be 10k.

It's exceedingly rare that HPL won't go 10k, at least after the engine's been cleaned a bit by prior HPL runs.

 

[mt23]

my two cents, PPPCMO 0w30 for both.

 

[scrllock]

IMO neither of these engines are anything special (no offense!).

I'm not as familiar with the FA24DIT, but if it has the same issues as the FA20DIT (fuel dilution, carbon build-up) I would want a low/mid-SAPS euro oil. Anything with MB 229.51/52 would be excellent--Mobil 1 ESP (0w30, 5w30, 0w40), Pennzoil Euro L/LX, Valvoline Euro XL-III for example.

Motul X-Clean EFE is the Subaru bandwagon oil atm, but I think it's a waste of money at the intervals that these fuel dilution monsters require. Same for HPL, it's certainly a good product, but I am skeptical that you would want to triple your OCI if you use a reliable analysis company for dilution (not BS labs!). And if you don't get a much longer interval out of it, what's the value?

This. Not a subaru guy, but Euro FS is so good and so universally applicable, it should be everyone's starting point for oils, deviating only as needed for particular application needs.

If you can find ESP X4, that's arguably better oil in some cases, but I've never seen it in any local store. And Supercar is basically the old ESP formula, so it's also going to be pretty dang good.

Really, any Mobil 1 0w40 is going to be a great choice if it's not the very rare C40 Gt blend.

As a Subaru guy, @Hohn and @SubieRubyRoo are giving you solid advice. The only way I know to get ESP X4 at a decent price is the Autozone 5qt+filter bundle. I would buy 0w40 FS for the FB25 and when it comes to my FA20, anything from my list above.

 

[Delta]

IMO neither of these engines are anything special (no offense!).

I'm not as familiar with the FA24DIT, but if it has the same issues as the FA20DIT (fuel dilution, carbon build-up) I would want a low/mid-SAPS euro oil. Anything with MB 229.51/52 would be excellent--Mobil 1 ESP (0w30, 5w30, 0w40), Pennzoil Euro L/LX, Valvoline Euro XL-III for example.

Motul X-Clean EFE is the Subaru bandwagon oil atm, but I think it's a waste of money at the intervals that these fuel dilution monsters require. Same for HPL, it's certainly a good product, but I am skeptical that you would want to triple your OCI if you use a reliable analysis company for dilution (not BS labs!). And if you don't get a much longer interval out of it, what's the value?


As a Subaru guy, @Hohn and @SubieRubyRoo are giving you solid advice. The only way I know to get ESP X4 at a decent price is the Autozone 5qt+filter bundle. I would buy 0w40 FS for the FB25 and when it comes to my FA20, anything from my list above.

FA24DIT is a much better engine than the FA20DIT, stronger internals, better turbo in stock form, etc, etc. It's still direct injection only, but I'm not sure if tuning is better to bring down the fuel dilution.

The Motul is definitely talked about a lot in the WRX community, but I know a lot like the Pennzoil Platinum (not the ultra version). I think extended OCI's would not be the recommendation here.

 

[scrllock]

FA24DIT is a much better engine than the FA20DIT, stronger internals, better turbo in stock form, etc, etc. It's still direct injection only, but I'm not sure if tuning is better to bring down the fuel dilution.

The Motul is definitely talked about a lot in the WRX community, but I know a lot like the Pennzoil Platinum (not the ultra version). I think extended OCI's would not be the recommendation here.

It's certainly good for more power but I don't know that they did anything to address the concerns I'd have as far as oil selection. PCV is still dead simple, and I think the injectors are still junk.

Thread 'Mobil 1 Extended Performance 5w30 3,200 miles; Subaru Outback XT 2.4L FA24DIT'

Apr 20, 2025

Just got this back.. fairly interesting but expected.
oil was in use from 12-17-24 to 4-12-25 (4 months)
mileage from 11111 to 14273 (3161mi)
Sump capacity 5qt.

• Rand
• Replies: 41
• Forum: Used Oil Analysis - Gasoline

• 

>5% fuel in ~3K is not much better. Not sure where the Pennzoil Platinum hype started, but yes, extended OCIs are not where I'd try to save money on a Subaru.

 

[Delta]

It's certainly good for more power but I don't know that they did anything to address the concerns I'd have as far as oil selection. PCV is still dead simple, and I think the injectors are still junk.

Thread 'Mobil 1 Extended Performance 5w30 3,200 miles; Subaru Outback XT 2.4L FA24DIT'

Apr 20, 2025

Just got this back.. fairly interesting but expected.
oil was in use from 12-17-24 to 4-12-25 (4 months)
mileage from 11111 to 14273 (3161mi)
Sump capacity 5qt.

• Rand
• Replies: 41
• Forum: Used Oil Analysis - Gasoline

• 

>5% fuel in ~3K is not much better. Not sure where the Pennzoil Platinum hype started, but yes, extended OCIs are not where I'd try to save money on a Subaru.

Ew

Definitely gonna have to get mine analyzed when I do the Spring oil change in my FA20DIT. I do run 93 octane so I wonder if that's a help.

 

[IndyIan]

I have no data, but Pennzoil Platinum Euro LX 0w30 seems to work well in our '18 2.5 Outback. A touch less engine noise. I run 10k km OCI's, and when doing an oil change, it comes out at 40-50C like oil still. It has all the nice specs to run it in lots of high hp/l engines.

I just did an oil change on my new to me '16 Impreza with cheap as possible 0W20 at about the same OCI and oil temp, and it was like water, splashing everywhere....