Quality oil for Subaru Ascent FA2.4F

gathermewool

Site Donor
Messages
9,016
Location
New England
Good point on the oil filter!

I know higher viscosity oils than OE recommended have been discussed on quite frequently, but I’m not so keen on doing it on newer engines going to 0w20 or even 0w16. Mainly for the reason of the timing chains as PimTac had mentioned. Also on that issue is variable cam timing setups. The ECM is looking for and is programmed for specific pressures based on the oil viscosity. Changing oil viscosity can and will effect that system. By how much? Too many variables to account for, every manufacture and engine is different.

The AVCS (VVT system) responds whether the oil is below freezing for 230F. Why would a few cSt viscosity difference matter??? It doesn’t.
 
Messages
1,015
Location
Sheboygan
and what if I told you the same engine specs elsewhere in the world calls for 5w30 and other viscosities notwithstanding 0w20...simple CAFE garbage is at play here in US of A

Where else in the world is Subaru's FA24F engine in usage? We're having this exact same conversation over at SubaruOutback.org right now and have been having it since the FA24F came into usage in 2018. The issue I have seen from UOA evidence is that most resource conserving 5w30 oils shear twice as quickly as 0w20 oils over the course of similar mileage intervals thus the end result on a UOA is nearly identical. I am looking into the usage of HDEO and oils with European approvals that are also SN, SN Plus, and/or SP rated that are not terribly expensive. It is a fine line to walk but ultimately I would be motivated to do the severe service 3000 mile OCI recommended by Subaru for this engine if I not already come up on the 6 month change timeframe as of yet.
 

TacoFergie

Thread starter
Messages
61
Location
Sioux City
Sorry I've been gone for a min guys, life gets busy as you know.

To my knowledge the FA24 is only available in North America in the Ascent, Outback XT and Legacy XT as of right now with rumors of a Forster XT soon. So there are no global standards to compare to as far this engine is concerned.

I realize that increasing the oil weight most likely will not have a negative impact on anything, but I'm not sure that it would have significant enough benefits for a daily driven street car that may see full throttle a couple times a month. Maybe I'm not well enough educated on the oil weight subject but I believe the main advantage would be to the engine bearings and during extreme service/heat.

No one to my knowledge has enough mechanical knowledge of this engine in regards to bearing clearances and long term testing yet besides Subaru. I know Prime Motoring has swapped an FA24 into a Crosstrek with a 6spd manual on E85, stock injectors, threw it on the dyno and continued to flog it for over 50 dyno runs over 3 days (so very little cool down time, if any) before running too lean and putting a hole through a piston. They ran the non-synthetic oil that came in the engine throughout the whole session and besides melting a piston they did not note any other damages to the engine. So I would assume that 0w-20 is plenty capable of handling engine load. Granted this isn't long term or being at 4500k into an oil change and then flogging it. But I feel like too much emphasis is put on oil weight for normal driving with stock engines. Again, I could be very wrong. This is just how I understand it currently.

I know I'm overthinking a simple subject that someone else has probably discussed already. But thats why we are all on this forum in the first place. We are nerds that can't simply just put any old oil in our cars, we are always looking for the best. You can't deny that.
 
Messages
2,393
Location
Paradise of Florida
Do you want to wait to find out what misengineerings an engine has?

A new engine comes out.... similar engineering from all the previous engines. Will it be just as iffy as some of the previous engines? or as good as newer engines from all the other automakers with similar technology?

So, if the vehicle is a keeper, and for most owners vehicles are disposal, make the adjustment with grades/intervals/filters for your driving style/location/expectations

Dyno doesn't include soccer mom short tripping and/or excessive idling, winter usage, and or excessive restarts.. Dyno floggin' is useless and meaningless. Theta-ii, Hyundai's headache, was dyno flogged/tested and ended up being a lemon.

A decade from now, maybe someone should bump this thread concerning the common issues this engine might have...
Does it have a timing chain/vvt/? Bet it will be common wear point
Does it have GDI? fuel dilution? IVD deposits? oil consumption from ring crud? Place your bets!
Does it have a good amount of boost and/or compression ratio and still recommend regular fuel?
Are the intervals extended like some automakers or did Subaru take a safe(hint) time/mileage interval, and why?

I haven't seen all these massively sheared full synthetic 5w30's.... Do you want a 9cst oil that shears to 7.5cst, or a 10.5cst oil that shears to 9cst?

And, bypass PSI on the filter is a fools argument. Don't use that filter because its lower/higher/whatever concerning bypass is silly.

I guess a decade or so from now we will know whether Subaru built a good engine. Until then, do want you want and reap what you sow.
 
Messages
1,015
Location
Sheboygan
I haven't seen all these massively sheared full synthetic 5w30's.... Do you want a 9cst oil that shears to 7.5cst, or a 10.5cst oil that shears to 9cst?

Here's a good place to start:


One FA24F owner got UOAs done for both Idemitsu 0w20 and Rotella Gas Truck 5w30. Both oils sheared down to a similar KV100 in the same engine under similar conditions and similar mileage.
 
Messages
2,393
Location
Paradise of Florida
Come back when you have a reasonable number of UOAs and not the few their. SOPUS and generic oils doesn't draw a conclusion for all.

And, if that engine is that tough on oil, I'd step up my recommendation to a euro/hdeo >3.5HTHS 30 grade.
 
Messages
11,961
Location
USA
Sorry I've been gone for a min guys, life gets busy as you know.

To my knowledge the FA24 is only available in North America in the Ascent, Outback XT and Legacy XT as of right now with rumors of a Forster XT soon. So there are no global standards to compare to as far this engine is concerned.

I realize that increasing the oil weight most likely will not have a negative impact on anything, but I'm not sure that it would have significant enough benefits for a daily driven street car that may see full throttle a couple times a month. Maybe I'm not well enough educated on the oil weight subject but I believe the main advantage would be to the engine bearings and during extreme service/heat.

No one to my knowledge has enough mechanical knowledge of this engine in regards to bearing clearances and long term testing yet besides Subaru. I know Prime Motoring has swapped an FA24 into a Crosstrek with a 6spd manual on E85, stock injectors, threw it on the dyno and continued to flog it for over 50 dyno runs over 3 days (so very little cool down time, if any) before running too lean and putting a hole through a piston. They ran the non-synthetic oil that came in the engine throughout the whole session and besides melting a piston they did not note any other damages to the engine. So I would assume that 0w-20 is plenty capable of handling engine load. Granted this isn't long term or being at 4500k into an oil change and then flogging it. But I feel like too much emphasis is put on oil weight for normal driving with stock engines. Again, I could be very wrong. This is just how I understand it currently.

I know I'm overthinking a simple subject that someone else has probably discussed already. But thats why we are all on this forum in the first place. We are nerds that can't simply just put any old oil in our cars, we are always looking for the best. You can't deny that.

I hope the Forester XT comes back :D
 
Messages
1,015
Location
Sheboygan
Come back when you have a reasonable number of UOAs and not the few their. SOPUS and generic oils doesn't draw a conclusion for all.

And, if that engine is that tough on oil, I'd step up my recommendation to a euro/hdeo >3.5HTHS 30 grade.

This is a very new engine that has not been out very long. You asked for data and this is what we have compiled so far, if you feel like the effort made and money spent by the people who have contributed to this effort is not sufficient anyone is welcome to contribute to include purchasing oil, filters, and UOA tests for the compilation of additional data :)
 

TacoFergie

Thread starter
Messages
61
Location
Sioux City
Do you want to wait to find out what misengineerings an engine has?

A new engine comes out.... similar engineering from all the previous engines. Will it be just as iffy as some of the previous engines? or as good as newer engines from all the other automakers with similar technology?

So, if the vehicle is a keeper, and for most owners vehicles are disposal, make the adjustment with grades/intervals/filters for your driving style/location/expectations

Dyno doesn't include soccer mom short tripping and/or excessive idling, winter usage, and or excessive restarts.. Dyno floggin' is useless and meaningless. Theta-ii, Hyundai's headache, was dyno flogged/tested and ended up being a lemon.

A decade from now, maybe someone should bump this thread concerning the common issues this engine might have...
Does it have a timing chain/vvt/? Bet it will be common wear point
Does it have GDI? fuel dilution? IVD deposits? oil consumption from ring crud? Place your bets!
Does it have a good amount of boost and/or compression ratio and still recommend regular fuel?
Are the intervals extended like some automakers or did Subaru take a safe(hint) time/mileage interval, and why?

I haven't seen all these massively sheared full synthetic 5w30's.... Do you want a 9cst oil that shears to 7.5cst, or a 10.5cst oil that shears to 9cst?

And, bypass PSI on the filter is a fools argument. Don't use that filter because its lower/higher/whatever concerning bypass is silly.

I guess a decade or so from now we will know whether Subaru built a good engine. Until then, do want you want and reap what you sow.

I agree that a dyno does not show long term wear or daily driven patterns. But it is still data to build off of. You are absolutely right, most people only own a vehicle for 2-3 years so this isn't even relevant to some. But this vehicle and my Tacoma are likely to stay with us for at least 10 years.

I plan on sticking with the OEM Subaru filter unless there is data showing it is inadequate. High quality and reasonable price, same with why I use a Toyota oi filter on my Toyota Tacoma.

I suppose in your experience, what engine oil and weight would you use if it were yours? Not trying to be smart, just trying to get a feel what others would consider.
 
Messages
2,393
Location
Paradise of Florida
If it were mine and a keeper for the grandkids:
I would use premium fuel always, as I do on all my turbo engines.

I practice a more aggressive oil change interval. So, if the manufacturer recommends 6000 mile oil/filter change interval, I'd change it every 4000 miles. Makes you wonder when most automakers are pushing OLM or simple 10k intervals and some don't. What do they know? What does Subaru recommend for an interval time/mileage for your model??

Since the engine is an unknown, but previous manufacturer's engines have had some issues, I look for common the history of engineering snafus. If it were mine, I would use synthetic 5w30 oil. Since I'm in a hot climate, I could easily step up to a 40 grade or higher HTHS 30 grade without even 2nd guessing it.

Concerning the oil filter, none of the OE filters have been impressive to me. Maybe I made the career mistake of working for 2 major filter manufacturers for several years. So, my view on filtration isn't NOT akin to cut-open filter reviews on websites or youbube or this website.
Sorry OE unknown flow/micron/capacity, I would use a full synthetic filter from Amsoil, Royalpurple, Fram, Purolator, Wix/Napa..... and have a habit of fitting the largest PN available. And, I would not let the bypass PSI be the silly only determinant of a filter.

And, I would check the oil level often keeping it at the full point.
 
Messages
575
Location
Washington, DC
Castrol Edge Extended Performance 0w20 (Gold Bottle)

API SP rated and is has the Mercedes Benz 229.71 approval, good luck finding a 0w20 with a high level European approval like that for less.
I was looking all over the place for the 229.71, C5 and Dexos 1 Gen 2 and stumbled into this oil also. I will be using this in my moms Forester and my 1.5Turbo DI equinox
 
Messages
146
Location
York, Pa
While I do agree with that for the most part. I do tend to overthink things with random topics on vehicles (mainly lighting) and especially being a new car I want to ensure that I do everything possible to keep it going for as long as possible or as long as we own it.

My 01 Outback has 220k-ish and I’ve had it for about 2 years. Has had piston slap since I got it. Hasn’t gotten worse and still keeps truckin. I’m sure the PO’s put whatever oil in that the shop put in and probably didn’t follow OCI’s very strictly. Lol
My beater Subaru had over 200k miles and it lived a hard life. I know it wasn't taken care of very well before I got it, but lasted me 4 years with what ever decent oil was on sale. It guzzled about 1 quart every 2 months. had very loud piston slap, still got great MPG, and never failed on me. Rear-wheel bearings and rust finally took it off the road. I did have some success quieting the piston slap by using Restore. It went from 2 8lb sledgehammers down to 2 framing hammers but didn't last long. I put over 50k with it and would still be driving but it cost too much to repair. I would not overthink the oil just use a brand name 5W-30 and be happy.
 
Messages
116
Location
NY
I have a 2019 Ascent and use 0w20 with no issues and no burning in 30k miles. Going to continue for the life of the vehicle. Nothing more to add but I thought I should chime in as another Ascent owner.
 

TacoFergie

Thread starter
Messages
61
Location
Sioux City
My beater Subaru had over 200k miles and it lived a hard life. I know it wasn't taken care of very well before I got it, but lasted me 4 years with what ever decent oil was on sale. It guzzled about 1 quart every 2 months. had very loud piston slap, still got great MPG, and never failed on me. Rear-wheel bearings and rust finally took it off the road. I did have some success quieting the piston slap by using Restore. It went from 2 8lb sledgehammers down to 2 framing hammers but didn't last long. I put over 50k with it and would still be driving but it cost too much to repair. I would not overthink the oil just use a brand name 5W-30 and be happy.

I'll have to give Restore a shot and see what happens. I like your analogy for going from sledge hammers to framing hammers! haha
 
Top