wouldnt a low NOACK score and a high HTHS rated oil be better in a turbo application ????
Turbo engines
- Thread starter silverbullet
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Start testing your oil, it's the only way to know or sure what's going on in YOUR engine. My DI turbo is a fuel diluter (granted, i have a four mile commute). Do you keep a quality synthetic in your engine when it has 3% fuel at 3500 miles even though the TBN is still 5.9? That's exactly the dilemma I face.
I gotta chime in on this discussion. I own a 2011 WRX with similar engine as yours. I've used 5w30 Mobil 1 Extended Performance (SM and SN) and 5w30 Pennzoil Ultra (SN) both of which are energy conserving oils.
My current fill is PU 5w30 (SN). My WRX consumed a small amount of M1EP. About .75 quart in 7500 miles which is very acceptable considering the length of service. Then I tried PU 5w30 for a 7500 mile service run. With PU my engine showed no signs of consumption so I decided to stick with PU.
I have been sending oil samples for analysis and it seems that both PU and M1EP 5w30 handle the long service just fine. You may want to send your oil samples just to make sure your engine behaves similar to mine. As an additional note I would recommend that you use Subaru's oil filters(the blue Honeywell can).
My driving consists of ~75%/~25% highway/city, ~15-20 minutes to work 1 way. >100 degrees Nevada desert summers and or decide to go over the mountain pass to California valley. I also do occasional spirited runs when I feel like it(to redline 2-3 different gears).
Keep in mind that I have no engine modifications. If you're planning on modifying your engine you will need to go for a more robust oil.
My last UOA thread:
Html:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Main=175900&Number=2627039#Post2627039
I've recently performed an oil change and about to send another sample next week so stop by to see my latest result.
My current fill is PU 5w30 (SN). My WRX consumed a small amount of M1EP. About .75 quart in 7500 miles which is very acceptable considering the length of service. Then I tried PU 5w30 for a 7500 mile service run. With PU my engine showed no signs of consumption so I decided to stick with PU.
I have been sending oil samples for analysis and it seems that both PU and M1EP 5w30 handle the long service just fine. You may want to send your oil samples just to make sure your engine behaves similar to mine. As an additional note I would recommend that you use Subaru's oil filters(the blue Honeywell can).
My driving consists of ~75%/~25% highway/city, ~15-20 minutes to work 1 way. >100 degrees Nevada desert summers and or decide to go over the mountain pass to California valley. I also do occasional spirited runs when I feel like it(to redline 2-3 different gears).
Keep in mind that I have no engine modifications. If you're planning on modifying your engine you will need to go for a more robust oil.
My last UOA thread:
Html:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Main=175900&Number=2627039#Post2627039
I've recently performed an oil change and about to send another sample next week so stop by to see my latest result.
Last edited:
Originally Posted By: silverbullet
Blusubie, I have read many people running more robust oils such as Rotella T6. But it also seems that many who use it are just following the pack (and out of warranty). Not that that is a bad thing. However, it doesn't prove that an energy conserving 5w30 oil shearing down to a 20 weight provides insufficient engine protection. Sure I've seen some UOAs indicating the shearing down of the oil. It may or may not have correlated to increased wear numbers. But I have not heard/read of widespread engine failures (more specifically WRXs) that were directly related to the failure of the oil to provide adequate protection. More often than not, the WRX failures I have read fall into a few categories such as 1) modified engines beyond reasonable levels for stock internals, 2) improper tunes, 3) manufacturing defects (certain batch of 2009 WRX engines).
I respect everybody's choices in running a more robust oil and I'm not trying to change it. However, at this point I don't buy it. Considering there are many engines (Chevy LSX engines and Ford V6 ecoboost, as well as many other turbo Subie engines as examples) running on the recommended 5w30 oil, we would be hearing of failures left and right.
However, I am here to learn so if people can provide solid data, information I am open to reading it.
One would think that turbo and bearing issues are limited to modified WRX's but that is not the case. I blew a turbo when my engine was stock and I was not running a 3.5 HTHS oil. My uoa's didn't indicate any problems with the exception of a minor uptick in lead to 10 ppm's. Although, I was exceeding Subaru's recommended 3,750 OCI for MY2010 and earlier.
And all you have to do is spend some time at subaruoutback.org, subaruforester.org, and legacygt.com and you will find turbo and bearing failure threads on stock Forester XT's, Outback XT's, and Legacy GT's running thin 5w30. Actually, about a month ago all of these forums simultaneously had failure threads within the first few pages.
I do believe the GF5 oils have improved and hopefully they will hold up well in Subaru turbos (any othermanufacurer comparison is irrelevant, IMO). There are many people with MY11 and 12's running RT6. The GC and RT6 examples that I mentioned above are having the oil installed by the dealer. I have friends at SoA, but I can't follow the tech department's oil advice when they say that "5W-40 conventional" may be used for replenishment (find me some of that) or when the Legacy and Outback manual says that you should stick with synthetic if you switch to it (very old logic).
Good luck and don't have too much faith in uoa's with low wear numbers. Low wear uoa's do not necessarily indicate that you won't have a turbo or bearing failure.
-Dennis
Blusubie, I have read many people running more robust oils such as Rotella T6. But it also seems that many who use it are just following the pack (and out of warranty). Not that that is a bad thing. However, it doesn't prove that an energy conserving 5w30 oil shearing down to a 20 weight provides insufficient engine protection. Sure I've seen some UOAs indicating the shearing down of the oil. It may or may not have correlated to increased wear numbers. But I have not heard/read of widespread engine failures (more specifically WRXs) that were directly related to the failure of the oil to provide adequate protection. More often than not, the WRX failures I have read fall into a few categories such as 1) modified engines beyond reasonable levels for stock internals, 2) improper tunes, 3) manufacturing defects (certain batch of 2009 WRX engines).
I respect everybody's choices in running a more robust oil and I'm not trying to change it. However, at this point I don't buy it. Considering there are many engines (Chevy LSX engines and Ford V6 ecoboost, as well as many other turbo Subie engines as examples) running on the recommended 5w30 oil, we would be hearing of failures left and right.
However, I am here to learn so if people can provide solid data, information I am open to reading it.
One would think that turbo and bearing issues are limited to modified WRX's but that is not the case. I blew a turbo when my engine was stock and I was not running a 3.5 HTHS oil. My uoa's didn't indicate any problems with the exception of a minor uptick in lead to 10 ppm's. Although, I was exceeding Subaru's recommended 3,750 OCI for MY2010 and earlier.
And all you have to do is spend some time at subaruoutback.org, subaruforester.org, and legacygt.com and you will find turbo and bearing failure threads on stock Forester XT's, Outback XT's, and Legacy GT's running thin 5w30. Actually, about a month ago all of these forums simultaneously had failure threads within the first few pages.
I do believe the GF5 oils have improved and hopefully they will hold up well in Subaru turbos (any othermanufacurer comparison is irrelevant, IMO). There are many people with MY11 and 12's running RT6. The GC and RT6 examples that I mentioned above are having the oil installed by the dealer. I have friends at SoA, but I can't follow the tech department's oil advice when they say that "5W-40 conventional" may be used for replenishment (find me some of that) or when the Legacy and Outback manual says that you should stick with synthetic if you switch to it (very old logic).
Good luck and don't have too much faith in uoa's with low wear numbers. Low wear uoa's do not necessarily indicate that you won't have a turbo or bearing failure.
-Dennis
My first recommendation for a turbo car is to use a full synthetic engine oil.
It is the extreme circumstances that must be accommodated.
I also note that umpteen jillion miles have been accumulated by turbo diesel trucks with dino oil.
It is the extreme circumstances that must be accommodated.
I also note that umpteen jillion miles have been accumulated by turbo diesel trucks with dino oil.
Alot of Subie-ers are using Rotella T6 in Boxer Turbos.
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