Opinions wanted! Best oil for 2013 WRX

[Brent_G]

Originally Posted By: KOUPATROOPA
I do plan on modding but I doubt I will ever do much track time, maybe a few autocrosses later in its life but who knows.

So knowing that, do you still have the same recommendation?

And can someone explain to me in laymans terms what the HTHS is and what 3.7 or 3.5 means in relation?


Okay let me toss my two pennies in and be done.

First off HTHS is High Temp High Shear, a test method to measure oil viscosity under "High Temp High Shear" conditions that would be useful in a engine such as valve train or bearing areas. HTHS correlates with film thickness under shear and hydrodynamic lubrication (bearings and such).

Also I have never owned a Subaru and I am a huge advocate of light oils as well high VI oils. However I have a lot of experience in high horsepower engines and running many different grades from 5w20 to 15w50 in 700hp+ big block mopars.

I do not feel 5w30 oil is a danger to your standard WRX. Yes many people have spun a bearing in these engines and some UOAs show higher wear on xw30 vs a heavier oil. However the WRX turbo by default is going to be ran much harder being a high performance car compared to a standard car, so failures will be a bit more common. The internet is an amazing tool for research as well, however people will be much more apt to complain about a failure compared to the thousands driving around happy as ever without any problems. Also UOAs are not a great reference to wear in an engine, rather condition of the oil itself.

With that said though I would run a bit heavier oil in this engine. I have yet to see an engine, mainly the bottom end bearings, fail from an oil too thick compared to too thin. When the oil film breaks down your bearings start going from hydrodynamic lubrication to boundary lubrication. With this your bearing depend on the additive film developed on the parts to lubricate, instead of the oil film itself, and if that fails you are left with very little to protect them. For most engines this is not a problem, however with the nature of your car it can become one.

I would go with M1 0W40, T6 5w40, or any 40 weight in general. Yes it is not optimal when cold or what is speced - however I would rather have a bit of extra in this case.

 

[gpshumway]

Originally Posted By: KOUPATROOPA
Well why would you switch if you aren't having any issues? Redline is a superior oil to M1 isn't it? Especially for turbocharged motors. This is just off of most of the UOA's I have seen on this site.


A few reasons, most importantly I like to experiment. Redline just changed their formula, so I'll be changing oil whether I want to or not. Granted the 2013+ Redline is the most similar oil by far to the 2009-2013 Redline. Other reasons include being willing to be the turbo EJ guinea pig for people like you who want a warranty friendly heavy duty oil. Also, the new Low-SAPS oils like M1 ESP are a bit of an unknown, one potential benefit over Redline is a reduction in deposits, especially intake deposits.

I wouldn't say Redline is unequivocally superior to M1 ESP. The VOA posted here indicates M1 has a similar NOACK, and we know M1 ESP has a cutting-edge additive package. Redline has a higher HTHS and temporary shear ratio, but ESP is still really good. Too close to call from the spec sheets which is "better".

Originally Posted By: KOUPATROOPA
I do plan on modding but I doubt I will ever do much track time, maybe a few autocrosses later in its life but who knows.

So knowing that, do you still have the same recommendation?

And can someone explain to me in laymans terms what the HTHS is and what 3.7 or 3.5 means in relation?


HTHS stands for High Temperature High Shear, it's a dynamic viscosity measurement which simulates worst-case conditions in the main/rod bearings at 302*F. It's in a unit called centistokes. It's a more accurate indicator of an oil's hydrodynamic bearing characteristics than the kinematic viscosity at 100*C which defines viscosity grades like 30wt and 40wt. 30wt oils fit in two categories, resource conserving with HTHS between 2.9 and 3.4 and heavy duty with HTHS>3.5. Modern 40wt oils are all "heavy duty" with HTHS>3.5.

 

[y_p_w]

Originally Posted By: Brent_G
I do not feel 5w30 oil is a danger to your standard WRX. Yes many people have spun a bearing in these engines and some UOAs show higher wear on xw30 vs a heavier oil. However the WRX turbo by default is going to be ran much harder being a high performance car compared to a standard car, so failures will be a bit more common. The internet is an amazing tool for research as well, however people will be much more apt to complain about a failure compared to the thousands driving around happy as ever without any problems. Also UOAs are not a great reference to wear in an engine, rather condition of the oil itself.

The sense I get from finding out more about turbos per se is that these days the turbos themselves probably aren't that hard on the motor oil. They're water cooled and constantly fed with a bath of cooler oil from the pump. Sure the oil is being used to cool down the bearings, but is that in an of itself that hard on the oil? I'm guessing it was when turbos were exclusively oil cooled and coking was a real problem because the heat and residual energy had nowhere left to go without the thermal siphon action of a coolant line.

Now what is probably tough on oil is that the boost is creating high pressures and high power per displacement. A lot of the speculation of what's been going on with Subaru turbo failures is that the screen gets plugged up that keeps chunks from entering the bearings. And with that they get oil starved. And what has been Subaru of America's answers to all this (along with their recommendations for a 5W-30 EC/RC oil)? Simply go to 3750 mile oil change intervals for any conditions. So maybe this takes care of the oil that is stressed out and it forces the owner to change the oil (and especially the filter) before a critical mass of stuff is there to plug up this screen.

http://blog.1aauto.com/2012/05/30/got-subaru-turbo-read/

Now I was thinking of this problem when I posted something about a separate lubrication system for turbos, whether that might be a separate oil line or even sealed greased bearings. One theory is that by sharing the oiling system, you're introducing the possibility that contaminants in the oil have to be separately filtered out, and can thus result in oil starvation to the turbo when a typically non-replaceable filter plugs up.

 

[KOUPATROOPA]

Wow guys, there is so much knowledge on this site it isn't even funny! Who knew there was so much to think about in regards to engine oil? Unfortunately I am no closer to a decision than I was when I asked the initial question (actually probably farther from it haha) BUT I feel like I have learned a lot from this thread which will only help me going forward and I plan on attempting to learn more about everything you guys have brought up, not sure how well I will comprehend it all though since it is so new to me haha.

Thanks again, love hearing all of your input!

 

[bluesubie]

gpshumway - I believe the Aussie Castrol Edge 5W-30 may be different from the Castrol OE Professional 5W-30 since the Aussie stuff meets VW502.

y_p_w - Subaru has removed those screens so turbo failures due to a blocked AVCS/turbo banjo bolt screen isn't an issue with the later models. Oddly, SoA allows a 7,500 mile interval on turbos after MY2011 and a turbo isn't automatically considered severe service like it was in the past. Also, the only current Subaru requiring the first oil change before 7,500 miles is the H6 Legacy and Outback. It's perfectly fine to run STI factory fill for 7,500 miles.

Robust add pack, but it's probably an xW-20.

KOUPATROOPA - I'm not close to making a decision either and look how long I've been here.

I change brands almost every interval (which might partially explain my Red Line consumption).

-Dennis

 

[05LGTLtd]

Another option I forgot about would be the Synpower 5w-40. My Napa stocks this oil, and they put it on sale a couple times a year. It doesn't light up any billboards with the spec sheet, but it does meet some tough euro specs:

http://www.valvoline.com/pdf/synpower.pdf

(The OTC version is the MST)

There are lots of good oils out there that would be more than adequate for a turbo Subaru. Based on price, availability, performance, and convenience; I still vote M1 0w-40. I'm not a XOM fanboy but having looked in to this for a while its hard to not keep coming to this conclusion.

 

[gpshumway]

Originally Posted By: bluesubie
gpshumway - I believe the Aussie Castrol Edge 5W-30 may be different from the Castrol OE Professional 5W-30 since the Aussie stuff meets VW502.


The Edge Professional PDS I have indicates OE is the VW 502/504 oil while LL03 is the 504/507 oil, so I believe Proffesional OE is the same as the Ausie oil.

KOUPATROOPA - I forgot to answer your question about lack of track use and my oil recommendation. Generally I still recommend either a HD 30wt or a 40wt. RT6 or TDT are probably overkill, but M1 0w40 is a great choice. Yes, it's virgin HTHS is the same as TDT, but it thins more (shears) in service, so in practice it's best to think of it as 0w35. It's only very slightly thicker than HD 30wt oils like M1 ESP 5w30. It's very slightly thicker than necessary for your use, but it's a screaming deal at $5/qt, easily the best value going in WRX oil. Redline is also a great choice and if you can get it cheap and aren't worried about warranty, go for it.

I also still recommend the oil cooler if you're going to mod. A modded WRX is basically an STI, and they come with a cooler. The oil/water unit in the STI is also an oil heater, which helps bring the oil up to temperature faster, which is win/win.

 

[y_p_w]

Originally Posted By: bluesubie
y_p_w - Subaru has removed those screens so turbo failures due to a blocked AVCS/turbo banjo bolt screen isn't an issue with the later models. Oddly, SoA allows a 7,500 mile interval on turbos after MY2011 and a turbo isn't automatically considered severe service like it was in the past. Also, the only current Subaru requiring the first oil change before 7,500 miles is the H6 Legacy and Outback. It's perfectly fine to run STI factory fill for 7,500 miles.

Robust add pack, but it's probably an xW-20.

I heard there was a service bulletin about it for all turbo models, but in fact not applicable to all models, and not my 2004 WRX. I think what they were trying to stress was more frequent oil changes.

Makes me wonder if they were trying to fix a problem that wasn't there. The reason for putting in this screen seemed to be more about a backup plan if oil filters get overloaded. And is it really that damaging to the bearings if stuff gets to the them to risk that the bearings get oil starved?

In any case, I'm committed to my WRX long term. Coming up on 105K miles and no turbo failure yet. I figure it's due to a timing belt, and it got new plugs at about 87K miles. I just bought a case of Wix 57712 filters along with another two Subaru specific filters (wondering if I should risk using the "NPN" brand one). Either I'll be sticking with this car or I'll be getting a new Subaru.

 

[il_signore97]

Originally Posted By: KOUPATROOPA
Wow guys, there is so much knowledge on this site it isn't even funny! Who knew there was so much to think about in regards to engine oil? Unfortunately I am no closer to a decision than I was when I asked the initial question (actually probably farther from it haha) BUT I feel like I have learned a lot from this thread which will only help me going forward and I plan on attempting to learn more about everything you guys have brought up, not sure how well I will comprehend it all though since it is so new to me haha.

Thanks again, love hearing all of your input!



I don't have a Subaru, so I won't comment on your oil choices as the others here have more experience in that area.

But I just wanted to add to all of the great information everyone has given you regarding the HTHS viscosity measurement of the particular oils that you can buy.

For a 40 grade oil (i.e. 0W40, 5W40, etc), it's pretty safe to assume that the HTHS value is > 3.5 cP. So if you were to use M1 0W40, you know you're getting something thicker.

For a 20 grade oil (none of which you would be considering here), you can pretty much assume that you will be getting an HTHS < 2.9 cP.

However, in a 30 grade oil (0W30, 5W30, 10W30, etc), there are 2 very different types out there. There are resource conserving 30 grade oils that have an HTHS of 2.9 - 3.4 cP, and then there are the heavier "Euro spec" 30 grade oils that do feature an HTHS of 3.5 or greater. Thus, you can walk into a store and pick up 2 different 5W30's or two different 0W30's, and one may have an HTHS of 3.0, while the other has an HTHS of 3.6 cP. Big difference. Be mindful of what you are buying based on the decision that you make. Also, it's another good thing to note that a 5W30 with an HTHS of 3.6 cP should perform similarly at operating temp to a 0W40 with the same HTHS.

Hope this helps a bit.

 

[CATERHAM]

Originally Posted By: KOUPATROOPA
Originally Posted By: CATERHAM

That's a complete myth propagated by some motorheads.
Thicker oil is not better unless your engine actually requires it and aside from the built in safety systems already mentioned (which you should check-out before jumping to conclusions), if one is planning on running increased boost, an oil pressure/oil temp' gauge should first be installed to fully appreciate the operational viscosity characteristic of your engine.
With that knowledge you'll likely learn that you don't need to run a heavier oil unless you plan on tracking the car.





I was basing my statement off of the actual engine manufacturer. Subaru of Japan specifically designed this engine for 5w40 applications but SOA recommends 5w30 in order to help you get better mpg's to stay within government regulated specs. Its been talked about quite often on NASIOC and other forums. If given a choice, I would follow the original engine manufacturers specs instead of SOA's but if I do that I risk voiding my warranty. For the first 10-12k miles I plan on following all necessary step to keep my warranty intact as it seems as though the ringland failures that can happen on these motors all happen in the first 12k miles. If I am one of the unlucky ones that this happens to, I don't want them coming back on me and denying coverage.

Here's the thing. The specified 5W-30 is plenty heavy enough to cover all normal driving conditions the engine will be normally subjected to. That may not include driving flat out on a track like Willow Springs in July when it's 110F but there is still a substantial viscosity reserve for normal aggressive driving as many UOAs on this site have established.

But is not rocket science, there is a maximum safe oil temp' for the spec' 5W-30 plus a safe minimum oil pressure spec' regardless of what oil you use. If you install oil gauges you eliminate and all doubt as to whether or not the spec' 5W-30 is too light for the why you drive your car.
A 0W/5W-40 grade oil is an inferior lube to the spec' 5W-30 on start-up all the way through to normal operating temp's and even higher. The advantage of the heavier oil grade will only become apparent if a certain very high oil temp' is achieved under maximum boost, a temp' you may never see.
The point is, at present you don't know if you're every seeing oil temp's high enough to benefit from a 40wt oil.

Notwithstanding the likelihood that Subaru have safety systems in place (as they do on their other sporty models) to deal with very high oil temp's, my advice is to install an oil gauge(s) and then you can make a proper informed decision on your oil viscosity selection.

 

[RobS]

Originally Posted By: bluesubie

PP is probably a good choice, but I wouldn't use any Resource Conserving oil in a Subaru turbo longer than 3,750 miles. Heck, I probably wouldn't run one in my application, period.

Shannow, yeah unfortunately our Edge 30 grade is barely a 30 grade at 9.8 cSt's, except for GC.

The owner's manual is a mess. 5W-30 is "required for optimum engine performance". 5W-40 or 10W-40 conventional is allowed for replenishment only, even though 5W-40 conventional doesn't exist, and thicker viscosity oil is REQUIRED in high temps.

I wouldn't hesitate running German Castrol, Mobil1 0W-40, or RT6 5W-40 in a new WRX. WIth Amsoil, I would probably go with HDD 5W-30, DEO 5W-40, or the new Full SAPS Euro 5W-40. Just say no to girly man oil.

-Dennis



Those three you mentioned (RT6, GC, M1 0-40) have been the only three oils I've ever used in my turbo Subies. I used to use RT6 strictly, but have since gone over to GC full time on my current 12 WRX and had virtually 0 consumption, opposed to the 1/4 qt ~3.5k I'd see on RT6.

I've been made aware of a
Just a heads up OP, if this is your first Subaru, get ready for the joys of reading your dipstick.

Oh, and the broken armrests on these

 

[bluesubie]

Originally Posted By: y_p_w
Originally Posted By: bluesubie
y_p_w - Subaru has removed those screens so turbo failures due to a blocked AVCS/turbo banjo bolt screen isn't an issue with the later models. Oddly, SoA allows a 7,500 mile interval on turbos after MY2011 and a turbo isn't automatically considered severe service like it was in the past. Also, the only current Subaru requiring the first oil change before 7,500 miles is the H6 Legacy and Outback. It's perfectly fine to run STI factory fill for 7,500 miles.

Robust add pack, but it's probably an xW-20.

I heard there was a service bulletin about it for all turbo models, but in fact not applicable to all models, and not my 2004 WRX. I think what they were trying to stress was more frequent oil changes.

Makes me wonder if they were trying to fix a problem that wasn't there. The reason for putting in this screen seemed to be more about a backup plan if oil filters get overloaded. And is it really that damaging to the bearings if stuff gets to the them to risk that the bearings get oil starved?

In any case, I'm committed to my WRX long term. Coming up on 105K miles and no turbo failure yet. I figure it's due to a timing belt, and it got new plugs at about 87K miles. I just bought a case of Wix 57712 filters along with another two Subaru specific filters (wondering if I should risk using the "NPN" brand one). Either I'll be sticking with this car or I'll be getting a new Subaru.

It was a very real problem which led to many oil starved turbos. You can read the TSB's at the end of this article:
http://store.forcedperformance.net/merchant2/merchant.mvc?Screen=Info_SubaruOil
There were even lots of stories about stock/dealer serviced cars suffering from oil starvation, usually right after the powertrain warranty expired.

A short time after these TSB's, SoA came out with another one that advised dealers to first do an engine flush to clear the screen. I've read cases where this actually worked and prevented a failure.

I seem to recall that they changed the design sometime around MY2008, although the oci wasn't extended until MY2011. Actually the very first MY2011's still listed 5W-40 and required 3,750 mile oci's and those owner's were notified via a mailed addendum from SoA that dropped 5W-40 and allowed 7,500 mile OCI's.

-Dennis

 

[KOUPATROOPA]

Ok guys sorry to bring this thread back form the dead but I have just decided to go stage 2 on my WRX and as a result I will be switching to a 40 weight oil. I did get PP on my last OC and it seems to be doing well, engine doesn't smell as hot after climbing my hill every day as it did with the OEM Subaru oil. Engine is also quieter with the PP than with the OEM oil.

I think my plan of attack going forward will be to use Mobil 1 0w40 in the winter months and RT6 5w40 in the Summer months as a few of you mentioned it is a thicker oil than M1. I also plan to start going 5k OCI.
Does anyone see anything wrong with this plan of attack? If so, please help educate me

 

[bluesubie]

You can probably run M1 0W-40 year 'round. Protune? Oil pressure gauge?

-Dennis

 

[gpshumway]

Yes, you can run M1 0w40 all year in WA. No problem.

If you insist on switching for the season, pick a pair of oils from the same manufacturer to hopefully get a similar additive package.

M1 0w40 - M1 TDT 5w40
PU 0w40 - PU 5w40 or RT6
GC 0w30 or BC 0w40 - Syntec 5w40

But again, any of the 0w40s will easily work all year. For that matter, the 5w40s will work all year.

 

[KOUPATROOPA]

Originally Posted By: bluesubie
You can probably run M1 0W-40 year 'round. Protune? Oil pressure gauge?

-Dennis


Are you asking if I am getting a protune and oil pressure gauge? If so, the answer is yes on the protune. I will be getting an oil pressure and temp gauge very soon, just not this month, this downpipe and tune are taking all my money for the near future.

 

[bluesubie]

Yes, that was my shorthand because I was in a rush.

Typically a good tuner will dial back some of the richness and you'll have less fuel dilution. There have actually been a few good 5W-30 uoa's on protuned WRX's.

I would stick with 0W-40 for now and keep an eye on oil pressure as well as do some uoa's.

-Dennis

 

[Raybo]

Redline 5-30 is awesome. You were right the first time.

Go with Redline.

In fact they sell a kit for that car...motor oil and trans oil and water wetter and a hat.

Get Redline in the trans asap and it will feel like a brand new car. My neighbor had one fast as [censored] that car I just could not get over the funky low speed motor boat sound of the engine. Sounded real good whem he got on it though.