IMPORTANT: Information on Subaru Motor Oil

[nhluhr]

From the May2007 TechTIPS bulletin:

We have received several inquires into the engine oil requirements for 2005MY and later vehicles. The owners’ manual refers to ILSAC and API oil grades, but you may ask “what are they”?

There are several organizations that develop, categorize, and license oil grades. The Society of Automotive Engineers (SAE) and the American Society of Testing Materials (ASTM) are involved in the performance parameters of oil development, but we will limit this discussion to the ILSAC and API organizations.

1) ILSAC – International Lubricant Standardization and Approval Committee. This committee is made up of American and Foreign Automotive Manufacturers that develop the standards/requirements for oil grades.

2) API – American Petroleum Institute. This organization licenses the approved oil with an API certification mark (‘starburst’ mark) which identifies the oil as meeting the current requirements set forth by ILSAC. The API also has a symbol of the ‘donut’ which contains their own API category identification, oil viscosity, and energy conserving designation, if applicable. The API has their own set of categories to identify oil grades. Prior to ILSAC’s inception, the API was the only organization to develop oil grade standards.

Since ILSAC’s existence in 1992, they have developed 4 different categories of oil grades, they are:
GF-1 first appeared in 1996
GF-2 first appeared in 1997
GF-3 first appeared in 2001
GF-4 first appeared in 2004

The categories are backwards-compatible with all previous categories, however they are not cross-compatible. For instance, GF-4 can be used in-lieu of GF-3, but GF-3 cannot be used when GF-4 is required.

API has a total of 11 gasoline engine categories in their history, starting with SA through SM (SI and SK have been omitted from the sequence).

Since the new GF-1 category, the API has worked to standardize their categories with the ILSAC standards. Although the categories are not entirely similar, they are compatible up to the current category. API has a separate energy conserving designation “Energy Conserving” which must be present for compatibility with the ILSAC categories.

Compatibility Chart
GF-1 / SH (Energy Conserving)
GF-2 / SJ (Energy Conserving)
GF-3 / SL (Energy Conserving)
GF-4 / SM (Energy Conserving)

All 2005MY:
Oil grade: ILSAC: GF-3 - or - API: SL (Energy Conserving) if not available SJ (Energy Conserving) may be used, SL is still the preferred grade.

All 2006MY and later:
Oil grade: ILSAC: GF-4 - or - API: SM (Energy Conserving)

GF-3 cannot be used in any 2006MY or later Subaru vehicles. The GF-4 category oil has the lowest phosphorus content of any oil preceding it. Phosphorus has been found to reduce the effectiveness and longevity of the emission system. There are several other important changes that were implemented to increase fuel economy and overall longevity of the engine.
Although most oils will contain both the GF-4 and SM (Energy Conserving) designation, it only needs to meet “GF-4” OR “SM”.

Currently the FHI/SIA factory fill oil is 0W-20 mineral oil for the H4 SOHC(w/o VVL) and 5W-30 mineral oil for all others. The oil is designated as SM and GF-4 and is manufactured by Shin-Nihon Petroleum (FHI) and Shell (SIA).

Clarifications:
1) Synthetic oil can be safely used provided the viscosity and oil grade classifications as noted in the Owners Manual are used. The oil change interval noted in the maintenance schedule must still be adhered to.
2) Severe Driving Conditions will require the oil change interval to be increased to 3,750 miles or 3.75 months. New for 2008: All turbocharged models are considered to be operated under severe driving conditions and require the oil interval of 3,750 miles or 3.75 months.

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[nhluhr]

Summary:

• Use a GF4/SM oil if you have a 2006 or later Subaru
• change your oil at 3750 miles
• use synthetic if you want

List of GF-4 (or SM) approved oils:
Amsoil ASL High Performance 5w30
Amsoil XLF Extended Life 5w30
Castrol Syntec 5w30
Mobil1 5w30
Mobil1 Extended Performance 5w30
Pennzoil Platinum 5w30
Redline Synthetic 5w30
Valvoline SynPower 5w30

What is NOT GF-4 (or SM) approved?
-Royal Purple
-Motul

[kaos200]

They are changing the recommendations only because of the findings about the emissions systems correct?
Seeing as how nothing changed internally (that we know of).

[nhluhr]

Nothing I know of, but apparently the GF-4 oils do promote better engine longevity? I really don't know.

[Evil STI]

Originally Posted by nhluhr

From the May2007 TechTIPS bulletin:

...New for 2008: All turbocharged models are considered to be operated under severe driving conditions and require the oil interval of 3,750 miles or 3.75 months.

It's refreshing for a manufacturer to admit that turbocharged cars are tougher on oil, despite all of the 'kamikazes' that like to brag about changing their oil at 4k, 5k, even 7k intervals.

[nhluhr]

I know it's not clear in that quote, but the service interval being 3750 is intended to be retroactive to all turbo subaru models - at least that is what I heard

[conker69]

Originally Posted by Evil STI

It's refreshing for a manufacturer to admit that turbocharged cars are tougher on oil, despite all of the 'kamikazes' that like to brag about changing their oil at 4k, 5k, even 7k intervals.

I have an oil analysis each time that proves my 5k+ interval is just fine.

[norexyet]

I have run Royal Purple for almost 40k miles, almost all miles were modded, no issues so far. Change it every 3500 miles.

[wcbjr]

Not going against the post, but I use(d) Mobil 1 synth for all 3 of my turbocharged Subarus. RS-T, WRX and LGT. No issues.

[Master2192]

^^^Thats fine, the issue is with SuperSyn, not the regular synthetic.

[302@12psi]

Guys Subaru isnt saying use X oil or the car will blow up and die within 4 months. It's very likely it will do fine with just about any oil with proper intervals (use common sense).

Subaru is saying if you want your warranty you better use the oil we say, at the intervals we say, and have proof of receipts to show you have done the same.

Getting into a oil debate over Subaru recommend oil change interval is silly.

Looking a tad bit farther you'd want to know why the sudden change? Personally I feel alot of people were probaly going pretty far into the interval because they were told when they bought the car 7,500 miles is okay. And they werent told that extream conditions would condone changing it every 3,500 miles.

And having worked in the Auto Industry for a bit I can safely say I personally think that if people were told they could go 7,500 miles they were probaly going 8k+ before changing it.

Or it could be more deep routed with the oil line banjo screen getting clogged at extended intervals and Subarus engineers/accountants came up with this fix.

[nhluhr]

Originally Posted by 302@12psi

they werent told that extream conditions would condone changing it every 3,500 miles.

This has been in the owners manual since day1... it's just that the phrase "extreme conditions" has been ill defined... Subaru now considers having a turbo to be "extreme".

[302@12psi]

Originally Posted by nhluhr

This has been in the owners manual since day1... it's just that the phrase "extreme conditions" has been ill defined... Subaru now considers having a turbo to be "extreme".

EDIT: You can consider it being in the manual as them being "informed" but I cant say for certain that every salesperson explained what "extreame" was or even pointed that part of the manual out. From my experiance the majority of people dont do little more but thumb through the owners manual.

I realize it's been in the owners manual...but honestly how many Joe Blows buyers who bought a Baja turbo, LGT, or even WRX that even read the manual or payed attention to it.

People push oil changes all the time...if you dont understand turbo motors are a tad bit different then Joe Housewife could very easily eat a few motors.

[Unabomber]

Thanks for this post, I updated the Oil FAQ with this information. Sadly....the debate will rage on as the oil dorks will come out of the woodwork. For the record...I'm staying out of this fight before the Junior Tribologists gang up on me.

[Jon [in CT]]

Originally Posted by nhluhr

I know it's not clear in that quote, but the service interval being 3750 is intended to be retroactive to all turbo subaru models - at least that is what I heard

If that were true then I'd expect to see service manual updates for this. So far, that hasn't occurred.

[uathatis]

Originally Posted by nhluhr

Summary:

• Use a GF4/SM oil if you have a 2006 or later Subaru
• change your oil at 3750 miles
• use synthetic if you want

List of GF-4 (or SM) approved oils:
Castrol Syntec 5w30
Redline Synthetic 5w30
Pennzoil Platinum 5w30
Mobil1 (classic, non-supersyn) 5w30

What is NOT GF-4 (or SM) approved?
-Royal Purple
-Motul
-Mobil1 SuperSyn

You can add Valvoline synpower 5w30 to that list nhluhr
GF-4 and SM approved





even though not many people use it....
i'm doing a change before 5k... on syn.. hopefully thats ok
well i'll say they just defined that so i'll just not wait as long next time

[BigJ04STi]

Is all of this only for 2005MY and 2006MY+??

Was there a difference for 2004?

Also, is there any actual engine differences from 2006+ why a these oil types are recommended? Specifically for the STi?? I know the WRX engine changed...

Personally I have used about 4 of the oils on that list in my 2004... and I did not like 2 of the 4. I say didn't like, by the fact 2 of the oils seemed to disappear on me, when the other 2 never burnt/depleted in any way at any time.

[lovesmysuby04]

nhluhr, I checked my bottles of Mobil 1 that have SuperSyn and they are GF4/SM approved.

[WolfPlayer]

One of the main things is that there has been a huge push to remove Phosphorous from oils due to plugging of catalytic converters. The federal emissions warranty lasts for, I believe, 80,000 miles. Thus, at 75,000 miles, if your catalytic converter goes bad then THEY HAVE to replace it. Simple as that. Thus, reducing phosphorous from oils is great for ensuring that the converters last that 80,000 miles. BTW, you have to have an engine that burns oil in order to plug your converter with a motor oil that contains a lot of phosphorous.

I'm not for the reduction of phosphorous. Why? ZDDP. ZDDP is a cheap but very effective additive to oils that seriously helps to reduce friction. With the new standards, the oil makers had to drastically reduce levels of ZDDP. That's not a good thing, IMHO. Just my thoughts. I even went to the extent of using M1R that has huge levels of ZDDP. Unfortunately, M1R has been discontinued

t

[nhluhr]

Originally Posted by lovesmysuby04

nhluhr, I checked my bottles of Mobil 1 that have SuperSyn and they are GF4/SM approved.

Ah, you're right - just checked Mobil1's website. I guess they must have retested. I was going off this quote from another tech forum:

> For some reason, Mobil 1 Extended Performance oil does not meet all of the
> ILSAC GF-4 standards. Could be that it does not meet the stricter fuel
> economy tests, or has too much phosphorus which can shorten the life of
> catalytic converters. It does meet the engine wear tests.

You've got that one. They have extra "SuperSyn" which is what Mobil calls a "high viscosity index polyalphaolefin". Basically what it does is serve as a base oil that also increases the viscosity index. I've heard using it also eliminates the need for other VI improvers in weights that previously needed it (or they now need less VI improver). So what you end up with is a slightly thicker oil (closer to the max for the viscosity range) at operating temps, which reduces fuel economy.

I am guessing they reduced the Phosphorous content to meet the new standard.

Also, to clarify, all Mobil1 motor oils contain "sypersyn" but the Extended Performance formula has a much higher content of the stuff.

[k mier]

Why is Subaru all of a sudden considering all turbo motors to be driven under extreme conditions and lowering the oil change interval? Because of problems with the tiny oil filters being clogged up with sludge and ruining motors. Read this link, http://legacygt.com/forums/showthread.php?t=58023 just another boring oil thread until post #123 where a Suby tech chimes in with his findings. These are not the banjo filters we all ready know about on the 04's, these are located in a very inaccessible spot. They are also recommending these filters be changed out at 30-60k.

[nhluhr]

k mier - with all due respect - they wouldn't need the little filters if not for the oil becoming sludgy/dirty. Since turbo engines generate significantly more heat and the turbo itself subjects the oil to massively greater sheer strain, a turbo engine being used lightly is equivalent to an N/A engine being used heavily, when it comes to oil longevity.

[nxttruck2002]

I use Motul 8100 5w30 100***37; synthetic (put it in a 9k). IIRC, their approvals are API SL / CF.

My car is running great! I have had no problems, nhluhr.

[Jon [in CT]]

Originally Posted by nhluhr

Since turbo engines generate significantly more heat and the turbo itself subjects the oil to massively greater sheer strain, a turbo engine being used lightly is equivalent to an N/A engine being used heavily, when it comes to oil longevity.

I don't buy this for turbo engines driven the way the vast majority of Subaru owners drive them, which is to say that manifold relative pressure is usually negative and is nearly always less than wastegate spring pressure.

BTW, the relevant pages, snipped from the May 2007 Subaru TechTIPS newsletter, are available as a PDF at xxxx bad link.

[nhluhr]

Originally Posted by nxttruck2002

I use Motul 8100 5w30 100% synthetic (put it in a 9k). IIRC, their approvals are API SL / CF.

My car is running great! I have had no problems, nhluhr.

I also use Motul 8100 5w30.