M1 EP 5w30 3.2k mi; Subaru Outback XT 2.4L FA24DIT

[john_pifer]

If the 0w20 oil is recommended by the manufacturer simply for economy I would otherwise agree if everything else remained the same. If the 5w30 oil flowed the same as the 0w20 throughout its possable operating range it would be a perect a choice. In warmer climates this would be perfect. sometimes oil passages designed (restricted) for a certain oil could be a issue at ultra low winter temperatures. And yes I am with most that a higher Vis "is Best" for longivity. I see the OP is in Ohio by his info. Its been real tough winter. edit I am in boston.

The Critic makes a good point. Does the increase in vis equate to longer engine life in the same engine under the exact conditions? its a question but is there an answer. I belive the answer is yes, and no. because it depends.

With DI suppose to be "Better" What needs to change to reduce this fuel/oil dilution issue? Indirect injection of some sort. Higher fuel pressure? Perhaps this is a question is best for another post...

Rand please keep us updated. I find this interesting as I am a 3 time subaru owner and appreciate its technology.

But there’s no indication that this engine’s bearing clearances or oil passageways have been downsized for a thinner oil grade.

 

[The Critic]

But there’s no indication that this engine’s bearing clearances or oil passageways have been downsized for a thinner oil grade.

Potentially correct, but it has also been proven that a thinner oil grade will suffice.

 

[tolian21]

Potentially correct, but it has also been proven that a thinner oil grade will suffice.

I can say the same thing about one grade thicker oil — no prove/evidence it will hurt anything

 

[bluesubie]

I can say the same thing about one grade thicker oil — no prove/evidence it will hurt anything

Subaru Japan allows 0W-20, 5W-30, and Euro 0W-30 in this engine.

 

[tolian21]

Subaru Japan allows 0W-20, 5W-30, and Euro 0W-30 in this engine.

Not surprised, another evidence of CAFE motivation to only list thinnest allowed viscosity.
Whats funny, after fuel dilution, 5w-30 ended up with Xw-20 viscosity.

 

[thunderous1335]

Plenty of TGDI engines use 0W20 successfully.

Not boxers

 

[notharry]

Agreed

 

[Rand]

Potentially correct, but it has also been proven that a thinner oil grade will suffice.

what am I losing using a 5w30? What are the potential consequences of a 6cst oil in a subaru 2.4l TGDI engine towing a trailer?
I'm still deciding if Iwant to UOA the fall oil change or just wait until next winter oil change.
my forecasted mileage will go down some this year so I'd estimate a 5000oci around oct-november. then another the following spring mar-apr with 3000 miles.

Years ago my dad had a 1979 Honda wagon with a 1.6 Compound Vortex Controled Combustion (CVCC) engine. This engine was state of the art in its day. Its design was used to increace the efficiancy of the engine (to meet emissions standards without the use of a Cat Converter. I googled IF this same CVCC techlology was being evauated as a means of improving combustion on DGFI engine. I apprears they are and Mahle and thers are doing it. The link is

https://www.google.com/search?q=cvc...E1NDc2ajBqN6gCALACAA&sourceid=chrome&ie=UTF-8

Getting super off topic from a UOA on a subaru there. also if using new acronyms please list it in the post.. DGFI? Dumb goat flatulence injector?

 

[The Critic]

what am I losing using a 5w30?

Warranty compliance. OEM's seem to be cracking down hard lately - across the board. Often need to show receipts of oil purchases when things get ugly.

 

[Rand]

Warranty compliance. OEM's seem to be cracking down hard lately - across the board. Often need to show receipts of oil purchases when things get ugly.

They can send my oil out for analysis it will show the correct viscosity
Also I'm far more worried about the CVT than the engine for warranty.. yet we get a hundred posts recommending non OEM CVT fluids in warranty.
0w20 is strictly for CAFE compliance. other countries have thicker oils listed for hot climates and severe service.. we just arent allowed to.

 

[The Critic]

They can send my oil out for analysis it will show the correct viscosity

They won't go that far. Usually once they see the receipts, if it isn't what they want to see, claim will stop.

 

[Rand]

They won't go that far. Usually once they see the receipts, if it isn't what they want to see, claim will stop.

but they have to prove the oil caused the issue? isnt that what all the aftermarket cvt fluid people say?
why would it be different for engine oil.

Are you sure you arent mixing up kia with subaru

Potentially correct, but it has also been proven that a thinner oil grade will suffice.

the engine has been out since 2020 I'd hardly call it proven.

 

[The Critic]

but they have to prove the oil caused the issue?

Maybe if you had the time and resources to take them to arbitration, but the MM act only says they can't require a brand - but they can require a spec.

Lately, it seems like every brand is doing - Toyota, Stellantis, etc. If a major failure occurs on a component that requires maintenance and dealer has to get approval from tech line to proceed, records are sometimes asked for. If you cannot provide them satisfactorily, claim is denied.

 

[tolian21]

Warranty compliance. OEM's seem to be cracking down hard lately - across the board. Often need to show receipts of oil purchases when things get ugly.

His viscosity is like 0w-20 if dealer does oil analysis. Receipt can be faked. This is fear mongering argument.

 

[dnewton3]

How about we stick on point; the UOA. The wear is just fine.
Let's not make this into yet another thick/tin debate.

 

[Impatient]

Personally, I look forward to seeing the ESP UOA’s, if you are planning to share them. I would think you can stretch the intervals to twice per year. Surely. (Er, Hopefully). It’s irrelevant, but I’ve stretched my 07 EJ turbo intervals to close to 5k, and still getting great results…that is different engine all the way around, but the Subaru recommendation was 3750. I don’t know fa24dit recommended interval, but I would hope with the typical euro HTHS you can get to 5k, though fuel might limit you beyond that. Have you tried premium fuel?

 

[buster]

>5% fuel dilution will make most/any oil drop a grade. I don't see anything unusual here other than a Cu spike. Fe is low. No oxidation. I see nothing wrong in this one other that high fuel dilution.

 

[edyvw]

Again it seems people are focused on wear and not what this test is designed to do: Used Oil Analysis!
Wear is irrelevant unless some huge spike that will indicate an issue.
Oil is way out of spec. for 5W30 after only 3.2k.
Move to ESP 0W30 or 5W30.

 

[Rand]

Personally, I look forward to seeing the ESP UOA’s, if you are planning to share them. I would think you can stretch the intervals to twice per year. Surely. (Er, Hopefully). It’s irrelevant, but I’ve stretched my 07 EJ turbo intervals to close to 5k, and still getting great results…that is different engine all the way around, but the Subaru recommendation was 3750. I don’t know fa24dit recommended interval, but I would hope with the typical euro HTHS you can get to 5k, though fuel might limit you beyond that. Have you tried premium fuel?

IIRC its 6k standard oci. Premium fuel is crazy here.. even costco.
for example yesterday at sheetz 88 is 2.46, 87 2.66, 92/93 was 4.09.

Costco today 2.56, 3.50

one of the main advantages of the fa24dit vs the fa20dit
the 2.4T is able to run 87 octane.

 

[ARCOgraphite]

Again it seems people are focused on wear and not what this test is designed to do: Used Oil Analysis!
Wear is irrelevant unless some huge spike that will indicate an issue.
Oil is way out of spec. for 5W30 after only 3.2k.
Move to ESP 0W30 or 5W30.

Jeepers it's fuel diluted, and the 710 Spec is 0W-20.

No use sacrificing engine response to a thick goo lubricant ... or is it?
You never know what margin of safety is required until you exceed it.


I will say it is interesting as a matter of comparison that Hyundai/Kia are spec'ing VAG 504,00/507 0W30 on their 2.5l Turbo models that don't have split crank throws.

side note: Anyone have bearing width spec on these two engines? Looking at Subaru cranks it appears at a casual glance they are severely are space limited due to the short boxer engine depth.

They employ knife edge "counterweights" and then apparently narrow the mains journal to allow more width for the rod journals. These things scare me and I have two in the drivway. One is filled with 0W-16. LOL.

Subaru Crankshaft