Looking for Oil/OCI Recommendation FA20DIT

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Hello,

Long time lurker, first time poster. We just bought a slightly used 2018 Subaru Forester XT Touring that has the FA20DIT engine. Bought it at 7k miles from a dealer who used it as a loaner car. They did the first oil change around 6k miles per maintenance schedule. We just got back from a 2500 mile road trip from out home in Oakland, CA to various locations in Orgeon and back. Now, at almost 10k miles I would like to do an oil change and use a proper oil brand and grade better suited to the engine and service conditions than the Subaru oil.

The trip included what I would consider severe conditions such as almost daily spirited driving on paved backroads as well as over 150 miles on dirt and gravel forest service roads and even 15 miles on the beach. We plan to keep this car for at least 10 years and this will be the normal use for this car. I have the Cobb Access Port coming in the mail and will be flashing over to their 91 octane stage 1 map with plans to get a downpipe/j-pipe and go stage 2 by the end of the year. For next year I am also considering other mods to the engine such as TGV/EGR deletes, upgraded intake and turbo inlet hose, charge pipe, larger top-mount-intercooler, electronic boost control solenoid, and probably other things the shop might recommend. All of these other things would need to be accompanied with a custom "pro" tune. I am also going to do other suspension and chassis mods including slightly-larger-diameter and slightly-heavier all terrain tires, but I don't know if those will affect oil choice or OCI.

After that long preamble, what oil should I use and how often should I change it? I would prefer to stick with readily available walmart oils for convenience and to save money, but I would consider the better oils like RP, Reline, Amsoil, etc if you guys think they will actually make the engine last longer. From what I read about oil filters, only the Subaru ones are recommended for these cars because of the high bypass spec that is difficult or impossible to find in the aftermarket.

Also, do you guys have any recommendations on the CVT and rear end oils?

Thank you,
 
For now a 10w-30, I like M1 HM 10w-30 because it’s AECA a3/b3 and has a high HTHS of 3.5 compared to most GF-5 10w-30 which are 3-3.1

Once you start with the modding a 15w-40 HDEO or one of the Porsche A40 certified 0w-40
5k oci
 
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Originally Posted By: SilverFusion2010
For now a 10w-30, I like M1 HM 10w-30 because it’s AECA a3/b3 and has a high HTHS of 3.5 compared to most GF-5 10w-30 which are 3-3.1

Once you start with the modding a 15w-40 HDEO or one of the Porsche A40 certified 0w-40
5k oci

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At the end of my current run on Castrol 0W-40, I'm going with a blend of Castrol Edge 10W-30/10W-40 High Mileage. Running these robust oils you should be fine going with a 5-6k mile OCI. I'm running a Cobb Stage I OTS as well.

I chose Castrol 0W-40 because the ZDDP is lower than Mobil 1 and I thought that maybe it would help with my constant catalytic converter CEL. But when I added a quart of Edge 10W-30 HM for make-up oil I noticed that my consumption subsided and my consumption hasn't subsided for the past 110,000+ miles.

I usually recommend Castrol 0W-40 over Mobil 1 for modified DIT's due to the lower calcium in Castrol since calcium is thought to contribute to LSPI and lower ZDDP is thought to be better at mitigating intake valve deposits. Subaru Japan has Castrol SLX Professional 5W-40 for all turbos and I think it's actually higher in SAPS than Castrol 0W-40 (although I haven't looked into this in a while). I've run Mobil 1 High Mileage 10W-30 in the past but switched because it didn't help with my consumption.

I have no experience with CVT oil but see a lot of recommendations to stick with OEM. Run any GL-5 in the rear diff.

Oh, cars with EGR/TGV deletes have shown much less fuel diltion and supposedly that helps with intake valve deposits as well. There's a lot of DIT uoa's on nasioc in the ongoing 2015+ WRX uoa thread.
 
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Rotella T6 5w30 or 5w40 or Chevron Delo 400LE 5w30 for 5k for now. You may wish to consider getting a UOA done after your first oil change after installing the mods. Napa has an oil analysis kit for about $15. Part number 4077.

Wix makes oil filters with the correct Subaru bypass. Napa's house brand filters are made by Wix. Napa Gold is the same as Wix, and Napa Platinum is the Wix XP wire-backed synthetic filter.

Castrol makes a great CVT fluid at a good price. It is often on sale for $5/qt (I think AAP/Carquest has it on sale now, actually). And if you ever need some when it's not on sale, Amazon has a good price on the case of 6.
 
I've been running Pennzoil Platinum 10W-30 in mine for the last couple of years, on the recommendation of members here.

No consumption, no issues. I posted a UOA on it.
 
My 2 cents.

Only use Subaru oil filter.

Use Amsoil Gear and CVT oil.

Engine oil choice is up for grabs. I'd ask one of their mechanics what they recommend. Just for kicks...
 
Since you're modding the engine, your warranty is off. That does open up some possible oil choices for you. I'd run walmart's Castrol 0w40 or Pennzoil Euro 0w40 in that engine in your case. Very few oils can brag about being Porsche A40 and MB 229.5, very tough specs.
 
Originally Posted By: oil_film_movies
Since you're modding the engine, your warranty is off. That does open up some possible oil choices for you. I'd run walmart's Castrol 0w40 or Pennzoil Euro 0w40 in that engine in your case. Very few oils can brag about being Porsche A40 and MB 229.5, very tough specs.


I actually recently had a negative experience running Pennzoil Ultra Euro 0w-40 in my 2011 Outback with EZ36. LOTS of oil consumption in 4.5K miles (It ate 2 full quarts *YIKES*). Haven't had ANY oil do that in this engine before. In fact, running PP 5w-30 and Castrol Edge 0w-40, consumption was so close to nill that You couldn't even tell via the dipstick.

Mayhaps a freak accident...but my '99 Porsche 911 (3.4 H6) didn't like the Penzzoil 0w-40 either. Anecdotal data points....but I won't be going back to it.
 
Thanks for all the advice guys. We plan on keeping this car for at least 10 years maybe 20 and will probably hand it down through the family after that. So what is more important, warranty coverage for a few years or long term engine health with the proper oil for this engine and usage scenarios? Am I expecting too much longevity out of this car with the goal of 250-275 whp? I have always figured that if I am going to modify it eventually, I may as well do it right away so as to enjoy the benefits. Then again, I have never had a car with a warranty before. Should I wait to modify?

I would like to clarify that when the car is driven aggressively it will nearly always be driven loaded down with our roadtrip gear and that the car will be wearing its taller diameter all terrain tires. And we like to seek out high elevation areas which means lots of uphill driving while loaded and with suboptimal gearing. All of which will increase the load the engine sees.

I read through the NASIOC Oil Guide which explained a few things for me, but it doesnt include much about the FA20DIT.

My local walmart didnt have the castrol or penzoil 0w40 so I picked up a quart of M1 15w50 and topped the engine off with about half a quart before heading out of town. We are near San Diego now and I will search for the right oil on the way back home next week.
 
Subaru introduced software changes to make LSPI less likely after the '14-15 FA20DITs (including mine) were recalled for it, but I'd still be careful about that potentially destructive issue and use a dexos1 Gen 2, dexos2, or SN+ oil. dexos2 opens up higher HTHS choices for modded engines, but good luck finding those oils at Walmart...I ran M1 5W30 ESP, which is now a dexos2 oil and has an HTHS of nearly 3.6, for a while and paid a pretty penny for the privilege ($11/liter at Pep Boys, somewhat cheaper on Amazon in quantity). If M1 10W30 HM is now an SN+ oil, that might be a really good choice for your application.

Subaru makes a special high torque CVT fluid for this engine, if you stick with OEM make sure the dealer actually uses it! I'm pretty sure I got the wrong fluid at 60kmiles and needed to have tranny work done at 80k, luckily under the extended 100kmile warranty Subaru has on all CVTs now...even after that I had to make a return trip to the dealer to get the right fluid put in. Your transmission has a filter added to the design after my '14 was made that might help you avoid these tranny problems.

I bought the special Subaru tool for intake valve cleaning and am glad that I have it, just pop and convenient vacuum hose off and hang the tool with a bottle of Subaru cleaner screwed into it from the hood. I tried using CRC intake valve cleaner spray once and the unfortunate geometry of the intake made that a mess with a MAF sensor cleaning needed to get things running right again afterwards.

Enjoy your ride, it just might be an example of the last of its kind...the XT was dropped for the '19 model year.
 
I probably should have mentioned that the weakest link in CVT 2.0 DIT’s is the CVT. A lot of people that go beyond Stage I report CVT issues. Have a look at nasic as well as subaruforester.org.
 
Originally Posted By: bluesubie
I probably should have mentioned that the weakest link in CVT 2.0 DIT’s is the CVT. A lot of people that go beyond Stage I report CVT issues. Have a look at nasic as well as subaruforester.org.

Excellent point, I believe the rule of thumb on subaruforester.org was 300HP max. Guess people were going to the 500HP range with the old 4 speed auto (4EAT??) in the older Foresters and were pretty shocked by the limitations of the CVT.
 
Originally Posted By: Virtus_Probi
Subaru introduced software changes to make LSPI less likely after the '14-15 FA20DITs (including mine) were recalled for it, but I'd still be careful about that potentially destructive issue and use a dexos1 Gen 2, dexos2, or SN+ oil. dexos2 opens up higher HTHS choices for modded engines, but good luck finding those oils at Walmart...I ran M1 5W30 ESP, which is now a dexos2 oil and has an HTHS of nearly 3.6, for a while and paid a pretty penny for the privilege ($11/liter at Pep Boys, somewhat cheaper on Amazon in quantity). If M1 10W30 HM is now an SN+ oil, that might be a really good choice for your application.

Subaru makes a special high torque CVT fluid for this engine, if you stick with OEM make sure the dealer actually uses it! I'm pretty sure I got the wrong fluid at 60kmiles and needed to have tranny work done at 80k, luckily under the extended 100kmile warranty Subaru has on all CVTs now...even after that I had to make a return trip to the dealer to get the right fluid put in. Your transmission has a filter added to the design after my '14 was made that might help you avoid these tranny problems.

I bought the special Subaru tool for intake valve cleaning and am glad that I have it, just pop and convenient vacuum hose off and hang the tool with a bottle of Subaru cleaner screwed into it from the hood. I tried using CRC intake valve cleaner spray once and the unfortunate geometry of the intake made that a mess with a MAF sensor cleaning needed to get things running right again afterwards.

Enjoy your ride, it just might be an example of the last of its kind...the XT was dropped for the '19 model year.


Aren't you supposed to apply the CRC beyond the MAF sensor?
 
Originally Posted By: pilot1226
Aren't you supposed to apply the CRC beyond the MAF sensor?

Heck yeah, but IIRC the intake took a right angle bend just past the MAF sensor and I had to kinda press the straw into the side in an attempt to make sure the cleaner was going the right way. I thought it was going OK as I was spraying, but my car ran pretty poorly until I gave the sensor a cleaning so I must have fouled it somehow.
Using the Subaru tool is very easy and has gone without a hitch...I'm sure the CRC spray is great for many, maybe most, applications.
 
Like SilverFusion said in the second post, I am thinking about going with the M1 HM 10w30 he recommended now and for Stage 1. Then maybe later stepping up to the Castrol EDGE 0W40 after mods and/or when I am expecting heavier use. I read on that NASIOC guide that an oil that is heavier than necessary will cause higher oil/piston temperatures and a higher risk of detonation. Doesn't a thicker oil also hurt fuel economy? Besides the M1 HM 10w30, I am having trouble finding the HD 30-weight oils in a reasonable price range.

The car is still running whatever oil Subaru put in(probably RC 5W30) plus half a quart of the M1 15W50. I have yet to flash to the Stage 1 map and the highest oil temp I have seen so far is 238 degrees in 85 degree heat. I was driving aggressively up a mountain to the Palomar Observatory while the car was heavily loaded. Do I need a 40 weight oil if I am getting oil temps that high two or three times per OCI?

Am I understanding things right here? The following is a list of different oil categories for this engine in order of increasing protection:
- Subaru calls for a API SN (Resource Conserving), ILASC GF-5, 5w30 Synthetic. Presumably use of any oil not meeting all of these requirements will void the warranty. These oils can be considered light duty oil and probably conform to one of the following ACEA specifications: A1/B1, A5/B5, C1, or C2. They have a HTHS between 2.9 and 3.4. Examples include: Subaru's oil, M1 5w30, PP 5w30, and Castrol EDGE 5w30.
- There is light-duty, but non-resource-conserving 30-weight oil. Conforms to all of the same ACEA specs as above. Example: M1 HM 5w30 (API SL, not SN)
- The next step for more protection would be a non-resource-conserving, "heavy-duty" 5w30. Here we have HTHS above 3.5. ACEA A3/B3, A3/B4, C3, C4, E7, or E9. Example: M1 HM 10w30 and M1 ESP 5w30. These non-RC 5w30 oils may also void the warranty, but I figure you have a little bit more of a leg to stand on since at least they are 30-weight oils and not 40-weight.
- Then you move up to a 40-weight oil. HTHS above 3.7. Example: Castrol EDGE 0w40.

What about LSPI and IVD? Perhaps LSPI is less likely with the CVT. Do I need to worry about SAPS or NOACK?

The Castrol EDGE 0w40 seems like a very good option because its pretty cheap ($4.95/qt when you buy the 5qt jug) from Walmart or Amazon Prime. It also has all the best certifications like the Porsche and the a3/b4 which I read is better than the a3/b3. However, I think the HTHS of ~3.7 might be overkill and because it is a 40-weight it is more likely to cause problems with the warranty.

On the topic of 40-weight oils, what about M1 0w40 Euro? I think it is an A3/B4 oil with HTHS of 3.6 and it is a buck or two cheaper at only 22.88 for the 5-quart ($4.60/qt) which is cheaper than both the Castrol and PP 0w40.

For a seemingly heavier-duty oil there is also a M1 HM 10w40 A3/B3 with a HTHS of 3.9 for the same $22.88/5-qt.

All the following oils are more expensive than I would like, considering the recommended 5k OCI. There is Castrol EDGE 5w30 C3 for about $7/qt. Castrol EDGE 5w30 A3/B4 for $8.10/qt and is in a gold bottle instead of black and I don't know why. Then you have Castrol EDGE 0w30 A3/B4 (German Castrol?) for about $8.50/qt. And there is the M1 ESP 5w30, but here we are talking about $10/qt.
 
Originally Posted By: redbeardmcgee
Like SilverFusion said in the second post, I am thinking about going with the M1 HM 10w30 he recommended now and for Stage 1. Then maybe later stepping up to the Castrol EDGE 0W40 after mods and/or when I am expecting heavier use. I read on that NASIOC guide that an oil that is heavier than necessary will cause higher oil/piston temperatures and a higher risk of detonation. Doesn't a thicker oil also hurt fuel economy? Besides the M1 HM 10w30, I am having trouble finding the HD 30-weight oils in a reasonable price range.

The car is still running whatever oil Subaru put in(probably RC 5W30) plus half a quart of the M1 15W50. I have yet to flash to the Stage 1 map and the highest oil temp I have seen so far is 238 degrees in 85 degree heat. I was driving aggressively up a mountain to the Palomar Observatory while the car was heavily loaded. Do I need a 40 weight oil if I am getting oil temps that high two or three times per OCI?

Am I understanding things right here? The following is a list of different oil categories for this engine in order of increasing protection:
- Subaru calls for a API SN (Resource Conserving), ILASC GF-5, 5w30 Synthetic. Presumably use of any oil not meeting all of these requirements will void the warranty. These oils can be considered light duty oil and probably conform to one of the following ACEA specifications: A1/B1, A5/B5, C1, or C2. They have a HTHS between 2.9 and 3.4. Examples include: Subaru's oil, M1 5w30, PP 5w30, and Castrol EDGE 5w30.
- There is light-duty, but non-resource-conserving 30-weight oil. Conforms to all of the same ACEA specs as above. Example: M1 HM 5w30 (API SL, not SN)
- The next step for more protection would be a non-resource-conserving, "heavy-duty" 5w30. Here we have HTHS above 3.5. ACEA A3/B3, A3/B4, C3, C4, E7, or E9. Example: M1 HM 10w30 and M1 ESP 5w30. These non-RC 5w30 oils may also void the warranty, but I figure you have a little bit more of a leg to stand on since at least they are 30-weight oils and not 40-weight.
- Then you move up to a 40-weight oil. HTHS above 3.7. Example: Castrol EDGE 0w40.

What about LSPI and IVD? Perhaps LSPI is less likely with the CVT. Do I need to worry about SAPS or NOACK?

The Castrol EDGE 0w40 seems like a very good option because its pretty cheap ($4.95/qt when you buy the 5qt jug) from Walmart or Amazon Prime. It also has all the best certifications like the Porsche and the a3/b4 which I read is better than the a3/b3. However, I think the HTHS of ~3.7 might be overkill and because it is a 40-weight it is more likely to cause problems with the warranty.

On the topic of 40-weight oils, what about M1 0w40 Euro? I think it is an A3/B4 oil with HTHS of 3.6 and it is a buck or two cheaper at only 22.88 for the 5-quart ($4.60/qt) which is cheaper than both the Castrol and PP 0w40.

For a seemingly heavier-duty oil there is also a M1 HM 10w40 A3/B3 with a HTHS of 3.9 for the same $22.88/5-qt.

All the following oils are more expensive than I would like, considering the recommended 5k OCI. There is Castrol EDGE 5w30 C3 for about $7/qt. Castrol EDGE 5w30 A3/B4 for $8.10/qt and is in a gold bottle instead of black and I don't know why. Then you have Castrol EDGE 0w30 A3/B4 (German Castrol?) for about $8.50/qt. And there is the M1 ESP 5w30, but here we are talking about $10/qt.


In the last year I have found Castrol on sale 4 times for under $20 a Jug at Walmart.
 
Originally Posted By: redbeardmcgee
Like SilverFusion said in the second post, I am thinking about going with the M1 HM 10w30 he recommended now and for Stage 1. Then maybe later stepping up to the Castrol EDGE 0W40 after mods and/or when I am expecting heavier use. I read on that NASIOC guide that an oil that is heavier than necessary will cause higher oil/piston temperatures and a higher risk of detonation. Doesn't a thicker oil also hurt fuel economy? Besides the M1 HM 10w30, I am having trouble finding the HD 30-weight oils in a reasonable price range.

The car is still running whatever oil Subaru put in(probably RC 5W30) plus half a quart of the M1 15W50. I have yet to flash to the Stage 1 map and the highest oil temp I have seen so far is 238 degrees in 85 degree heat. I was driving aggressively up a mountain to the Palomar Observatory while the car was heavily loaded. Do I need a 40 weight oil if I am getting oil temps that high two or three times per OCI?

Am I understanding things right here? The following is a list of different oil categories for this engine in order of increasing protection:
- Subaru calls for a API SN (Resource Conserving), ILASC GF-5, 5w30 Synthetic. Presumably use of any oil not meeting all of these requirements will void the warranty. These oils can be considered light duty oil and probably conform to one of the following ACEA specifications: A1/B1, A5/B5, C1, or C2. They have a HTHS between 2.9 and 3.4. Examples include: Subaru's oil, M1 5w30, PP 5w30, and Castrol EDGE 5w30.
- There is light-duty, but non-resource-conserving 30-weight oil. Conforms to all of the same ACEA specs as above. Example: M1 HM 5w30 (API SL, not SN)
- The next step for more protection would be a non-resource-conserving, "heavy-duty" 5w30. Here we have HTHS above 3.5. ACEA A3/B3, A3/B4, C3, C4, E7, or E9. Example: M1 HM 10w30 and M1 ESP 5w30. These non-RC 5w30 oils may also void the warranty, but I figure you have a little bit more of a leg to stand on since at least they are 30-weight oils and not 40-weight.
- Then you move up to a 40-weight oil. HTHS above 3.7. Example: Castrol EDGE 0w40.

What about LSPI and IVD? Perhaps LSPI is less likely with the CVT. Do I need to worry about SAPS or NOACK?

The Castrol EDGE 0w40 seems like a very good option because its pretty cheap ($4.95/qt when you buy the 5qt jug) from Walmart or Amazon Prime. It also has all the best certifications like the Porsche and the a3/b4 which I read is better than the a3/b3. However, I think the HTHS of ~3.7 might be overkill and because it is a 40-weight it is more likely to cause problems with the warranty.

On the topic of 40-weight oils, what about M1 0w40 Euro? I think it is an A3/B4 oil with HTHS of 3.6 and it is a buck or two cheaper at only 22.88 for the 5-quart ($4.60/qt) which is cheaper than both the Castrol and PP 0w40.

For a seemingly heavier-duty oil there is also a M1 HM 10w40 A3/B3 with a HTHS of 3.9 for the same $22.88/5-qt.

All the following oils are more expensive than I would like, considering the recommended 5k OCI. There is Castrol EDGE 5w30 C3 for about $7/qt. Castrol EDGE 5w30 A3/B4 for $8.10/qt and is in a gold bottle instead of black and I don't know why. Then you have Castrol EDGE 0w30 A3/B4 (German Castrol?) for about $8.50/qt. And there is the M1 ESP 5w30, but here we are talking about $10/qt.

I think LSPI would be more of a concern with the CVT since you may driving around in lower revs unless you’re in sport mode. I’d probably avoid “I” mode for this reason. Subaru Japan doesn’t seem too concerned about IVD and LSPI as they still allow high SAPS ACEA A3 oils in DIT’s.

Edge 0W40 actually has lower ZDDP and calcium than other 0W40’s. Warranty schmarranty. You’re going to do a reflash.
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Note that the manual has language that thicker viscosity is required in high temps.
 
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