best oil for turbo Subaru

[Garak]

Originally Posted By: bluesubie
"For 2010 and earlier turbocharged engines, Subaru also recommends the Subaru synthetic 5W-30 motor oil."

How many years has Subaru been waffling on this issue? They continue to call for an API/ILSAC type oil, when there are other specifications they could quote, or come up with their own. Instead, they use nebulous wording. If they want an A1/B1 synthetic 0w-20, they should say so. If they want an A5/B5 30 grade or an A3/B4 oil, they should also say so. It's not that difficult.

 

[wemay]

Subie clan...
How do we know what the % of WRX owners is that have blown an engine/turbo on either dino or syn is? Most of the guys on the forums that i read of, having had either unfortunate result, has had a modified vehicle running T-6 or another syn. Can we attribute all failures to the oil, and to take it a step further, dino oil?

Or am i off base here...

 

[05LGTLtd]

I forgot to mention Synpower 5w-40. It meets some pretty tough specs, and I have a few oci's worth in the stash.

A friend with an '06 LGT runs Motul exclusively. Of course Motul, redline, or amsoil will run some $$$.

As far as SN goes, it is weighted more toward economy than protection, that's my opinion. Xw-40s skip that limitation.

 

[Hollow]

Originally Posted By: Ramblejam
Originally Posted By: Hollow
Small sump on a crammed in turbo engine for longer intervals on conventional will get you a new turbo at best and a new engine at worse.


Nonsense. You just can't lump every single conventional oil together.

Of note, there are many small sump turbo owners out there running 15w-40 (Delo, Delvac, Rotella) with great success.



15w40 =/= 5w30 energy conserving oil.

*sigh* This is what I get for presuming people know what I'm talking about. Allow me to spell it out.

In this particular case of a turbocharged DOHC 2.5 Subaru engine with a 4.5 quart sump that originally called for a conventional 5w30 resource conserving API SM oil to be changed at 7500 miles under normal driving conditions was a very bad idea. Due to a high rate of banjo bolt filter failures, cooked turbos, and blown up engines Subaru changed the requirements (as have been posted already)to require synthetic at the severe service interval of 3750 miles for this engine (covering their bases on both ends in my opinion, I've seen decent UOA's for synthetic in these engines in the 5000-7500 range. But that is what is their official statement via TSB).

So, no I do not think it is wise to run a resource conserving conventional oil in this particular vehicle for an OCI of longer than 3000-4000 miles based upon all available information on multiple Subaru forums, Subaru itself through a TSB, and general observation of oil performance in this situation and vehicle.

Specific enough now?

 

[wemay]

Originally Posted By: Hollow

I do not think it is wise to run a resource conserving conventional oil in this particular vehicle for an OCI of longer than 3000-4000 miles based upon all available information on multiple Subaru forums, Subaru itself through a TSB, and general observation of oil performance in this situation and vehicle.


Doesn't appear to be irrational to me...

 

[bluesubie]

Originally Posted By: Garak
Originally Posted By: bluesubie
"For 2010 and earlier turbocharged engines, Subaru also recommends the Subaru synthetic 5W-30 motor oil."

How many years has Subaru been waffling on this issue? They continue to call for an API/ILSAC type oil, when there are other specifications they could quote, or come up with their own. Instead, they use nebulous wording. If they want an A1/B1 synthetic 0w-20, they should say so. If they want an A5/B5 30 grade or an A3/B4 oil, they should also say so. It's not that difficult.

Well at least the OP's model year still allowed several grades depending on ambient temp and operating conditions. His owner manual allows 10W-40 (or it could have been switched to 5W-40 in his model year) down to -4F.

I'm more concerned about the newer Forester turbos running thin 5W-30. They're having some bad fuel dilution in winter (3-6% on Blackstone) and they're having misfire codes and one 2014 owner had fuel injectors replaced.

After several misfire codes, gathermewool here had an ECM update without any info on what the dealer actually did, and there is no TSB in N. America, while Oz (and the EU?) has actually had a recall.

-Dennis

 

[bluesubie]

Originally Posted By: wemay
Subie clan...
How do we know what the % of WRX owners is that have blown an engine/turbo on either dino or syn is? Most of the guys on the forums that i read of, having had either unfortunate result, has had a modified vehicle running T-6 or another syn. Can we attribute all failures to the oil, and to take it a step further, dino oil?

Or am i off base here...

For the recent model years, there have indeed been a few bearing failures even on dealer serviced, stock WRX's running synthetic 5W-30.

For the OP's model year, there have been many, many turbo failures on cars running conventional and even synthetic due to oil screen clogging that a few of us have mentioned. This happened to me with only 20k on a turbo, likely due to me pushing my OCI's too far.

Sometime before Subaru started recommending or requiring "synthetic", this TSB was released about the screens:
http://store.forcedperformance.net/merchant2/graphics/subaru_oil/02-106-08.pdf

Yes, some failures are attributed to modifications, but no idea on how many failures on conventional oil since so few people run conventional in these cars. Although, I do see people every now and then that do (and change their oil every 2,500-3,000 miles).

Because of the issues we Subaru owners have highlighted, there is just no point in running conventional or synthetic GF5 5W-30, IMO. There is nothing to be gained.

-Dennis

 

[A_Harman]

Originally Posted By: Clevy
Originally Posted By: Hollow
Oil - Quality synthetic in a 0/5W30/40
Filter - OEM or Wix 57712 to meet Subaru's unusually high bypass spec

I wouldn't run convention more than 3000-4000 in this engine, the turbo gets hot. Synthetic should be good for 5000-7000. 5000 if you don't want to do any analysis and want a safe number.

My personal oils would be QSUD 5w30, Rotella T6 5w40, or Mobil1 0w40.




So all those big rigs with their diesels and huge turbos using conventional should worry about their turbo getting hot then,since your using that as some sort of reason not to use a conventional.
Turbos get hot everywhere they are fitted. Using hot exhaust gasses to spin an impeller will do that pretty effectively,yet even those big rigs,and diesel trucks out there who run mileages sky high,on conventional oil,and their turbos last just fine.
See where I'm going here.......



You don't appreciate the difference in the operating environments between diesel and gasoline turbos. Diesel pre-turbine EGT's max out at about 1250F, and gasoline pre-turbine temperatures easily top 1650F. This is why gasoline turbo's are fitted with water-cooled bearing housings (most of the time).

 

[wemay]

Originally Posted By: bluesubie
Originally Posted By: wemay
Subie clan...
How do we know what the % of WRX owners is that have blown an engine/turbo on either dino or syn is? Most of the guys on the forums that i read of, having had either unfortunate result, has had a modified vehicle running T-6 or another syn. Can we attribute all failures to the oil, and to take it a step further, dino oil?

Or am i off base here...

For the recent model years, there have indeed been a few bearing failures even on dealer serviced, stock WRX's running synthetic 5W-30.

For the OP's model year, there have been many, many turbo failures on cars running conventional and even synthetic due to oil screen clogging that a few of us have mentioned. This happened to me with only 20k on a turbo, likely due to me pushing my OCI's too far.

Sometime before Subaru started recommending or requiring "synthetic", this TSB was released about the screens:
http://store.forcedperformance.net/merchant2/graphics/subaru_oil/02-106-08.pdf

Yes, some failures are attributed to modifications, but no idea on how many failures on conventional oil since so few people run conventional in these cars. Although, I do see people every now and then that do (and change their oil every 2,500-3,000 miles).

Because of the issues we Subaru owners have highlighted, there is just no point in running conventional or synthetic GF5 5W-30, IMO. There is nothing to be gained.

-Dennis


Great explanation Dennis. I used to own a 2003 Evo8 that ran conv oil until I sold it, with 175k miles. A buddy of mine did the same with his 'bug-eyed' WRX. Subaru is a great company, im sure Fuji industries will straighten things out.

 

[SubLGT]

Originally Posted By: bluesubie
………..OT: (actually on topic since the OP could be affected).
SubLGT - I just had a valve job on my FXT as well. More reading here:

http://allwheeldriveauto.com/seattle-area-subaru-burnt-exhaust-valve/?no_redirect=true

-Dennis


How many miles on your FXT? Did you have an early warning from cold engine misfires?

 

[bluesubie]

Originally Posted By: SubLGT
Originally Posted By: bluesubie
………..OT: (actually on topic since the OP could be affected).
SubLGT - I just had a valve job on my FXT as well. More reading here:

http://allwheeldriveauto.com/seattle-area-subaru-burnt-exhaust-valve/?no_redirect=true

-Dennis


How many miles on your FXT? Did you have an early warning from cold engine misfires?


About 130k miles and ~two years of misfires and idle problems.