21 Subaru Ascent - M1 EP 0w20

Total waste of $$$ doing a uoa before 25K miles. Maybe I missed this but I thought the FA20/FA24 were speced for 30 wt oil. 5W-30 or even 10W-30 synthetic are fine for all year around
The FA24 specs 0W-20. In Japan some cars spec 0W-16 so it’s probably just a matter of time before n/a cars here spec 0W-16.
 
The FA24 specs 0W-20. In Japan some cars spec 0W-16 so it’s probably just a matter of time before n/a cars here spec 0W-16.
My '18 FA20 DIT is speced for 30 wt. The non turbo FAs are 20 wt. There is no way I would run the FA24 DET on 20 wt. Then again I run my FB25 with 30 wt. oil.
 
Total waste of $$$ doing a uoa before 25K miles. Maybe I missed this but I thought the FA20/FA24 were speced for 30 wt oil. 5W-30 or even 10W-30 synthetic are fine for all year around

Where did this belief come from? 🤨

So you suggest we just blindly run 25,000 miles (that’s several YEARS worth of use for the average Joe) without getting ANY DATA from your Brand New engine in your Brand New car? 🤔

What if you have crazy fuel dilution from a defective, leaky fuel injector and had you sampled the oil earlier, you would have noticed this and addressed it with the dealership for warranty repair but instead you BLINDLY drove it for several years causing EXTRA WEAR before FINALLY addressing the problem at 25,000 miles. 🤦🏻‍♂️

Sounds idiotic to me.

I sampled the factory fill from several new engines over the years. I monitored the break-in metals quickly drop and stabilize within the first few oil changes. I don’t see how that’s a waste of money to see that my Brand New engine is healthy and good to go from the first oil change. 😜😎👍🏼
 
Where did this belief come from? 🤨


Sounds idiotic to me.
To each his own. I'm sampling m y '22 Forester and I know its idiotic. And I am even using 30 wt. I'll post when I get the results.
And you know that when subaru recomments 30 wt for the FA20 turbo and now 20wt for the F24 Turbo they are sacrificing engine life for a .5 mpg economy boost.

Then again with DI only the valves will be one big carbon cube by 75K miles.
 
There's the possibility that ESP may get hotter more quickly due to more friction from a thicker oil.

Any chance your wife would use the flappy paddles to hold the revs a little higher when the car is cold? That would help bring the car up to temp more quickly. Does she use remote start? I cringe when Outback owner's complain that the car cuts off after 10 minutes using remote start. They are really loading up the oil with fuel in those cases.

I wouldn't think ESP would get warmer faster than AFE while both being 0w30. However that's why I switched to OAI because Blackstone doesn't indicate fuel dilution. I should have done that from the start, live and learn.

I doubt I can convince my wife to use the flappy paddles on cold mornings. Between coffee, music and morning traffic she has enough distractions. lol I finally got her to stop using the remote start more than once in the morning. But this is the first year, so I don't know how that will effect it since I just started with OAI also.

What made you decide to to do uoas?
Total waste of $$$ doing a uoa before 25K miles. Maybe I missed this but I thought the FA20/FA24 were speced for 30 wt oil. 5W-30 or even 10W-30 synthetic are fine for all year around

You do realize what forum and sub forum you're on right? BITOG and specifically UOA's are for the overly data concerned individuals. We are not always rational people and this is a good place for us to nerd out. The FA24 is spec'd for 0w20, not sure on the FA20 but I would assume the same. A 10w30 would be just too much in my environment where we often see temps below 0F. A light 5w30 like Penzoil would probably be fine though.
 
Have you actually had Subaru look at this? I assume it is still under warranty. It's absolutely possible your high pressure fuel pump is leaking fuel. This amount of fuel dilution and/or shear seems absurd.

I haven't had Subaru take a look at it yet regarding fuel dilution. It is common on the FA24 and many report rising oil levels on the Ascent and Outback forums. I have not seen anyone get the issue fixed though some have had fuel pumps replaced. No one has confirmed it fixed the issue nor have they said it was the high or low pressure fuel pump. I haven't seen anyone report that injectors were replaced or having stuck injectors either. But it's completely possible.

I do agree that this amount of dilution seems outrageous. I need to get it back to the dealer anyways because the front suspension is making noise. There has been a rash of bad front struts on the Ascent. To me it seems more like the mount, but Subaru replaces the entire assembly. Plus I want them to re-address the slow warm up or never even getting to temp. As much as I love this car for it's interior space and highway cruising, I really think Subaru's quality is starting to slump a bit. I really wanted a Highlander Hybrid, but the interior is more cramped and a similarly equipped Highlander Hybrid was almost $15k more at the time.
 
I wouldn't think ESP would get warmer faster than AFE while both being 0w30. However that's why I switched to OAI because Blackstone doesn't indicate fuel dilution. I should have done that from the start, live and learn.

I doubt I can convince my wife to use the flappy paddles on cold mornings. Between coffee, music and morning traffic she has enough distractions. lol I finally got her to stop using the remote start more than once in the morning. But this is the first year, so I don't know how that will effect it since I just started with OAI also.
ESP has a higher viscosity at 100C as well as a higher HTHS so it is thicker than AFE. Not all manufactures list HTHS but it has to have at least an HTHS of 3.5 to meet the specs that it meets.

I haven't had Subaru take a look at it yet regarding fuel dilution. It is common on the FA24 and many report rising oil levels on the Ascent and Outback forums. I have not seen anyone get the issue fixed though some have had fuel pumps replaced. No one has confirmed it fixed the issue nor have they said it was the high or low pressure fuel pump. I haven't seen anyone report that injectors were replaced or having stuck injectors either. But it's completely possible.

I do agree that this amount of dilution seems outrageous. I need to get it back to the dealer anyways because the front suspension is making noise. There has been a rash of bad front struts on the Ascent. To me it seems more like the mount, but Subaru replaces the entire assembly. Plus I want them to re-address the slow warm up or never even getting to temp. As much as I love this car for it's interior space and highway cruising, I really think Subaru's quality is starting to slump a bit. I really wanted a Highlander Hybrid, but the interior is more cramped and a similarly equipped Highlander Hybrid was almost $15k more at the time.

I've heard of one case where a Forester owner got a dealer to look at the injectors on a FA20 DIT based on an OAI UOA. I seem to recall that the dealer ended up finding a leaky injector. I think that's the exception rather than the rule since I've heard more cases of dealers not taking action based on a uoa. I believe it's in a 2.0 UOA sticky on the Forester forum although I couldn't find it.
 
ESP has a higher viscosity at 100C as well as a higher HTHS so it is thicker than AFE. Not all manufactures list HTHS but it has to have at least an HTHS of 3.5 to meet the specs that it meets.



I've heard of one case where a Forester owner got a dealer to look at the injectors on a FA20 DIT based on an OAI UOA. I seem to recall that the dealer ended up finding a leaky injector. I think that's the exception rather than the rule since I've heard more cases of dealers not taking action based on a uoa. I believe it's in a 2.0 UOA sticky on the Forester forum although I couldn't find it.
ESP has 12cSt vs AFE 11.5cSt according to Mobil's site. I haven't been able to find HTHS specs on either. I think there was a UOA of AFE, but I'd have to dig for that one.

I'm not too terribly worried about warranty issues since I don't think I'll have any mechanical issues with the engine, though there is a minute amount of concern. But if there is an issue at some point I do track my maintenance on Fuelly (no receipts though) and if it came down to it, I have the UOA's too. The hope is to keep this car for 10yrs or so. So finding an oil that holds up or potentially finding an issue before it's a problem is my main concern. It really surprises me how much fuel dilution there, even being a DI engine. I think the slow engine warm-up is mostly responsible for the heavy fuel dilution. If others have been oblivious to the fuel dilution and gone 100k+ on barrel stock 0w20 with 6k mile OCI's, I figure what I am doing is overkill for the better. I know UOA's can sometimes raise unreasonable amounts of concern, but I like data. haha
 
ESP has 12cSt vs AFE 11.5cSt according to Mobil's site. I haven't been able to find HTHS specs on either. I think there was a UOA of AFE, but I'd have to dig for that one.

I'm not too terribly worried about warranty issues since I don't think I'll have any mechanical issues with the engine, though there is a minute amount of concern. But if there is an issue at some point I do track my maintenance on Fuelly (no receipts though) and if it came down to it, I have the UOA's too. The hope is to keep this car for 10yrs or so. So finding an oil that holds up or potentially finding an issue before it's a problem is my main concern. It really surprises me how much fuel dilution there, even being a DI engine. I think the slow engine warm-up is mostly responsible for the heavy fuel dilution. If others have been oblivious to the fuel dilution and gone 100k+ on barrel stock 0w20 with 6k mile OCI's, I figure what I am doing is overkill for the better. I know UOA's can sometimes raise unreasonable amounts of concern, but I like data. haha
AFE would need to be 3.4 or lower to meet GF-6. Typically GF-6 xW-30's are ~3.0 - 3.2.
 
If I were to try another 0w20, is there that you guys would recommend? I was using Mobil 0w20 EP which seems like it's been reformulated, maybe for the better? I like the idea of HPL's 0w20's, but the cost is a bit hard to justify for an experiment, I've considered contacting them on their thoughts as well. Idemitsu 0w20 seems stout, as does TGMO 0w20. Maybe even Schaeffers 0w20 since that is available locally?

Only reason I ask is that on the Ascent forums one of the admins (Subaru Ambassador as well) is claiming that there is a probability of warranty claims being denied due to the wrong oil being used in the event of engine issues. Even went as far as saying "Subaru can be very serious about people using the wrong oil in the car". While I doubt Subaru would even ask or even the likelihood of an issue arising where oil could be a potential factor, it is something I have considered. I can see this claim if oil changes are absolutely neglected or if I used 15w40 HDEO, but I doubt 0w30. I know this has been discussed a little here and multiple times on other threads also, but there are too many factors that play into this to have a definitive answer.
 
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If I were to try another 0w20, is there that you guys would recommend? I was using Mobil 0w20 EP which seems like it's been reformulated, maybe for the better? I like the idea of HPL's 0w20's, but the cost is a bit hard to justify for an experiment, I've considered contacting them on their thoughts as well. Idemitsu 0w20 seems stout, as does TGMO 0w20. Maybe even Schaeffers 0w20 since that is available locally?

Only reason I ask is that on the Ascent forums one of the admins (Subaru Ambassador as well) is claiming that there is a probability of warranty claims being denied due to the wrong oil being used in the event of engine issues. Even went as far as saying "Subaru can be very serious about people using the wrong oil in the car". While I doubt Subaru would even ask or even the likelihood of an issue arising where oil could be a potential factor, it is something I have considered. I can see this claim if oil changes are absolutely neglected or if I used 15w40 HDEO, but I doubt 0w30. I know this has been discussed a little here and multiple times on other threads also, but there are too many factors that play into this to have a definitive answer.
I wouldn't take anything that Ambassador says seriously, I was kicked out of that group by him for recommending an Xw30 weight oil to someone outside of warranty. He gave me a warning to play nice and then started telling me I didnt understand how oil viscosity works because I stated an oil is thicker when cold than hot and then immediately removed me from that group which I enjoyed being a part of for 3 years and giving genuinely helpful advice to folks asking for it.

If you run a thicker oil and with fuel dilution it tests as a 20 hot then who is to say that's a problem coming back as the recommended viscosity?
 
If I were to try another 0w20, is there that you guys would recommend? I was using Mobil 0w20 EP which seems like it's been reformulated, maybe for the better? I like the idea of HPL's 0w20's, but the cost is a bit hard to justify for an experiment, I've considered contacting them on their thoughts as well. Idemitsu 0w20 seems stout, as does TGMO 0w20. Maybe even Schaeffers 0w20 since that is available locally?

Only reason I ask is that on the Ascent forums one of the admins (Subaru Ambassador as well) is claiming that there is a probability of warranty claims being denied due to the wrong oil being used in the event of engine issues. Even went as far as saying "Subaru can be very serious about people using the wrong oil in the car". While I doubt Subaru would even ask or even the likelihood of an issue arising where oil could be a potential factor, it is something I have considered. I can see this claim if oil changes are absolutely neglected or if I used 15w40 HDEO, but I doubt 0w30. I know this has been discussed a little here and multiple times on other threads also, but there are too many factors that play into this to have a definitive answer.
I know who you’re referring to. He is only relaying what he was advised. Someone on the Outback forum was able to get SoA to state that 0W-30 was fine. They (SoA) didn’t at first but he persisted based on the ambiguous language in the manual about thicker oil being required for high temps.

It’s not in the UOA sticky but it’s in the general Gen 6 oil discussion sticky. I also posted the JDM FA24 WRX manual there where it mentions 5W-30 and Euro 0W-30 are allowed.
#I’mtoolazytolookforit.
 
I know who you’re referring to. He is only relaying what he was advised. Someone on the Outback forum was able to get SoA to state that 0W-30 was fine. They (SoA) didn’t at first but he persisted based on the ambiguous language in the manual about thicker oil being required for high temps.

It’s not in the UOA sticky but it’s in the general Gen 6 oil discussion sticky. I also posted the JDM FA24 WRX manual there where it mentions 5W-30 and Euro 0W-30 are allowed.
#I’mtoolazytolookforit.
What are the chances of Subaru wanting a UOA for a warrantied long block? I think all they care about is if maintenance was done on time.
 
I wouldn't take anything that Ambassador says seriously, I was kicked out of that group by him for recommending an Xw30 weight oil to someone outside of warranty. He gave me a warning to play nice and then started telling me I didnt understand how oil viscosity works because I stated an oil is thicker when cold than hot and then immediately removed me from that group which I enjoyed being a part of for 3 years and giving genuinely helpful advice to folks asking for it.

If you run a thicker oil and with fuel dilution it tests as a 20 hot then who is to say that's a problem coming back as the recommended viscosity?

I can believe it. He is very helpful in many cases and has a ton of inside info. But the level of by the book standards and lack of thinking outside the box. To be fair though, I think on that forum and the Ascent FB page (not so much the modded ascent FB page) mechanical subjects can be taken out of context very easily since the majority of people are not mechanically savvy enough to know any different and just take things at face value. It might as well be a minivan forum to be honest.

Oil ending up at a 20wt at the end of the OCI is my thought as well.

I know who you’re referring to. He is only relaying what he was advised. Someone on the Outback forum was able to get SoA to state that 0W-30 was fine. They (SoA) didn’t at first but he persisted based on the ambiguous language in the manual about thicker oil being required for high temps.

It’s not in the UOA sticky but it’s in the general Gen 6 oil discussion sticky. I also posted the JDM FA24 WRX manual there where it mentions 5W-30 and Euro 0W-30 are allowed.
#I’mtoolazytolookforit.

I absolutely agree that he is essentially playing it safe. I tried a quick search for that thread in the OB forums but couldn’t find it. I’ll have to search again when I have a little more time. Are there any key words that would help? I tried 5w30 and “JDM FA24 WRX manual” specifying the 6th gen sub forum. I think I’ve read that before but can’t recall what the thread title was or how deep in the thread it was.

I'd start with a 5w30 synthetic

I did consider that, but I like the 0wXX for its cold start flow since I’m in IA and we see cold starts below 0F, which is coming up next week. PUP or PP would probably be fine as they are it’s one of the thinnest 5w30’s, PP is only 1cSt above Mobil EP 0w20. So PP would likely end up in the high 6.xx cSt in about 5K miles.
 
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