Suggest an oil for STI 2.5 HO Turbo in SoCal

[aaronpeck]

Hello guys,

I've been a reader "searcher" here at BITOG for about a year or more now. I've never posted because i've been able to find alot of information by simply searching.

Today i'm posting because i'm at a cross roards when it comes to my oil / gear lube. I own a 2005 Subaru Impreza WRX STI. The recommended OCI's from Subaru are 7,500 miles on a standard GF-3 5w-30 dino oil in which the factory and dealerships use Valvoline. I however ran the factory fill for the first 7,500 and then immediatly switched to Mobil 1 0w-40.

I chose M1 0w-40 for its obviously excellent base numbers but not on UOA's as I have not found any nor would I know how to read them correctly. Ever since I switched to Mobil 1 i've been having consumption issues in which I know my car is partly to blame because Subaru's are notorous oil eaters. I have heard though that some have gotten their consumption to slow to a minimal amount over the 7,500 with different oils.

Now you know the history, let me tell you what i'm looking for:

This is for 7,500 OCI's for light daily driving and a rare push to the redline.

1. A synthetic and a conventional motor oil recommendation. Please recommend which weight you think I should use and why.

2. A synthetic and a conventional gear oil recommendation.Please recommend which weight you think I should use and why.

NOTE: Please also LIST what you feel is the general acception for the BEST "numbers / statistics / additive wise" synthetic and conventional oils and also best filter available.

Qualities im looking for in an oil:

1. Peformance
2. Protection
3. Stability
4. Quality
5. Value

Thanks guys!

 

[m2200b]

There are 134 WRX STI oil UOAs posted.
Over half are M1 users.
Have you looked at those as most get comments on how it looks or what works for them from other WRX owners?

 

[Auto-Union]

I'd say try Shell Rotella T Synth 5w-40, just on a whim. MaxLife Synth 10w-30 would be another, since you don't drive hard.

 

[AndyH]

Running Castrol Syntec (a.k.a., "German Castrol" or simply "GC") 0W-30 in my COBB Stage 1 '05 STi. Here's my latest UOA on this oil which also shows the results from my previous runs of conventional and semi-synthetic oils:
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic&f=3&t=003237

As far as oil filters go, you can't do much better than the OEM Subaru oil filters (Part #15208AA100). I bought a bunch in bulk from a Subaru dealer who sells parts online.

BTW,

to BITOG!

 

[Unabomber]

Did you read the Oil FAQ on NASIOC?

http://forums.nasioc.com/forums/showthread.php?t=499177

That being said, Subaru motors can stand just about any oil though 5w30 is the recommended weight. If you see consumption issues, you might try something thicker. Mobil 1 is nice just because it's cheap and readily available.

http://forums.nasioc.com/forums/showthread.php?t=995498 talks about tranny and differential fluids in depth, so go there and get your learn on as some of it is VERY Subaru specific in that the knowledge posted there is based on TONS of Subaru owners' experiences and is more valuable than the advice you'd get here (no offense BITOG guys).

 

[bluesubie]

Wow, I can't believe you kept factory fill in there for 7,500 miles! It must have been a 15 weight by the end.

There a few 2.5T owner's that have posted UOA's in the UOA forum running GC. One STi posted a UOA that included 45 drag passes.

I run it in my Forester XT, but it's a little to thick for my winter application (I get high fuel due to short trips). Subaru's also break-in very slowly so your wear metals only start to come down at 10k and don't get to normal in some cases until over 20k.

I recently switched to Specialty Formulations MTL-R gear oil. You can do some searching here to read more. I've used synthetic gear oil in Subaru's (Amsoil, Motul Gear 300, Motylgear blend) since 1998 and this is my favorite so far.
Add some MTL-P (75/85) if you prefer something thinner, but still want a GL5.

-Dennis

 

[jmacmaster]

I'd run Mobil 1 or Mobil 1 EP 5W-30. I run the latter in my Forester, which has the same engine as your STI, without the turbo.

 

[aaronpeck]

Why cant you beleave I ran the factory fill for 7500 miles? How can you make statements like "15 weight by the end." when you can even for sure say exactly what oil even comes in Subaru's or how long the factory oil is stable until.

Subaru's recommended OCI are 7,500 on STI's. Therefore I don't think it is ridiculous for me to follow the recommendation. I do know that Subaru uses a standard GF-3 or better 5w-30 conventional dino oil from the factory but of what manufacturer and with what additives im unsure. I can however assume that Subaru tested the car and ran it extremly hard on this oil is R&D. Likely harder then i'll ever drive it. They wouldnt recommend it if it wasnt the right thing to do car care / money / enviroment wise. Yes, even though I own a higher polluting car (still considered LEV), I do still think that people chaning their oil every 3,000 is an absolutly ridiculous practice. If they feel their current DINO isnt good passed 5,000 plus miles then maybe they should shell out a couple more bucks and get an oil that is. Either buy 8 qts of oil for 6,000 miles at $2 a piece or buy 4 qt if synthetic at $4 a piece for 6,000 miles. You just spent the same money and saved the hastle of changing the oil one more time.


Honestly my post is basically asking:

-What is the finest NUMBERS and UOA wise ?w-30 or 40 weight synthetic available. Money aside.

-What is the finest NUMBERS and UOA wise ?w-30 or 40 weight conventional available. Money aside.

-What is the finest NUMBERS and UOA wise 75w-80/90 gear oil available. Money aside.

-What is the finest NUMBERS and USAGE wise oil filters available. Money aside.


BTW, Dennis I beleave the MTL-R is now both GL-4/5 dual certified.

-Aaron

 

[Winston]

There is no absolute finest. Everyone will have an opinion.

One of the finest Synthetics is Redline. Great engine oil and transmission/gear oil.

However, Mola's gear oil is probably better than Redline.

If you call a Grp III oil conventional, probably Amsoil's XL7500 is the best. It shows great UOA's.

Havoline, is a readily availible Dino and it is cheap too. Well respected and and has a ton of moly in it. (nothing compared to Redline though)

BTW are you saying Montclair, CA because you don't want to admit that you live in Oakland?

 

[sprintman]

I'd run Dave Grandquists rec from Redline or SF oils. I have a Sube (not WRX)

 

[AndyH]

quote:

---

Originally posted by aaronpeck:
Why cant you beleave I ran the factory fill for 7500 miles? How can you make statements like "15 weight by the end." when you can even for sure say exactly what oil even comes in Subaru's or how long the factory oil is stable until.

Subaru's recommended OCI are 7,500 on STI's. Therefore I don't think it is ridiculous for me to follow the recommendation. I do know that Subaru uses a standard GF-3 or better 5w-30 conventional dino oil from the factory but of what manufacturer and with what additives im unsure. I can however assume that Subaru tested the car and ran it extremly hard on this oil is R&D. Likely harder then i'll ever drive it. They wouldnt recommend it if it wasnt the right thing to do car care / money / enviroment wise.

---

Aaron,

You might want to check out this UOA on a 2006 STi with only 2,080 miles on the factory fill:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003573

The oil sheared down to a 20-weight oil in this short time. While Dennis thinks your oil may have sheared down to a 15-weight oil over 7,500 miles (I think he was exagerating a little bit), I'd bet your oil sheared down into the 20-weight range as well. FWIW, I dropped my factory-fill oil at approx. 2,500 miles and ran 2,500 mile oil change intervals until I hit 10,000 miles. Now I'm running a full synthetic oil on a 5,000 mile interval. Based on my first UOA of this oil I can probably run it further, but I'd prefer to change it out at a nice even 5,000 figure as I run my STi pretty hard, and I do have a COBB Stage 1 ECU re-map.

 

[aaronpeck]

I'm fine with the factory fill at a sheared 20w. Fact of the matter is the car wasnt beat on in break in. As long as the additives were still active and the oil was above 15-20w range im fine. Its been said many times before, the EJ257 is easy on oil. I tend to try and leave factory fills in for the duration on the first recommended OCI. I think that at times its more beneficial than changing it too early. The factory fill is completely overloaded with moly and I figure if Subaru had good results breaking in the EJ257 with that oil than I should too. So far I have. My C/R tests have been perfection. The car runs flawless... What more could I ask for.

Anyways, as far as oil goes. Being that my car is costing me a pretty penny everywhere I decided that its in my best interest to go with conventional dino oil recommended by Subaru. The oil I have chosen is Havoline 5w-30 with a PureONE filter. I will be changing my OCI's from 7500mi with synthetic to the SOA recommended servere service of 3,750mi. I have a Blackstone kit here with me now. I will UOA the Havoline after this change and see if its possible I can re-extend my OCI's to 5,000mi of even 7,500mi on Havoline.

Its cheap. Its effective.

 

[surfstar]

Glad we could help.