2012 WRX- Redline 5w-30 vs Mobil 0w-40

[CATERHAM]

Originally Posted By: 05LGTLtd


T6, M1 0w40, GC, PU 5/10w30 are all proven fi Subaru oils.


That's quite a viscosity range, HTHSV 3.1cP (PU 5W-30) to 4.0cP (T6).
If the lighter oil works, with all the inherent advantages on start-up, etc not to mention being the spec'd grade, it doesn't make much sense to use anything else particularly for street use.

 

[05LGTLtd]

Originally Posted By: CATERHAM
Originally Posted By: 05LGTLtd


T6, M1 0w40, GC, PU 5/10w30 are all proven fi Subaru oils.


That's quite a viscosity range, HTHSV 3.1cP (PU 5W-30) to 4.0cP (T6).
If the lighter oil works, with all the inherent advantages on start-up, etc not to mention being the spec'd grade, it doesn't make much sense to use anything else particularly for street use.


That is quite a range, yes. The 10w30 PU at 3.2 or 3.3 (icrrn) or the M1 and GC at 3.5ish are the middle of the pack. Depending on climate, if you want to run thin, then 5w30 PU has given some good feedback here and elsewhere. But if your moderately (me) or heavily modified, then going a little higher on the hths scale is possible. Also have to factor local temps, driving application, availability and cost.

My manual specs 10w40 and 20w50 as applicable for my engine. I've said it before but I'll say it again: at no time between 2002 and 2012 did subau make any significant tolerance changes in the ej construction. They did change their spec's and I think they did so because... A. They think that the average consumer is not responsible/capable enough to choose an oil from their chart in the manual. B. They did so for precieved legal/cafe reasons. If any one can find me a tsb where Subaru decided to change the oil grade recommendation retroactively or proof they changed the engines internally to tighter tolerance, I'll recant.

Just because an oil has the Honda turbo spec, don't automatically assume it won't shear down in asubaru in a 3750oci. I put more faith in the A3 spec and some of the tougher euro manufacture's specs that also meet A3 from VW, Porsche and MB.

 

[05LGTLtd]

The one significant change that was made was the removal of the oil cooler from the wrx. I think that was 2008+ my's. Forgot about that one for a minute.

 

[Josh8519]

So that means a thicker oil is even better for the 2008+ then right?

Also, what exactly causes oil consumption? For some reason a lot of Subaru owners claim their cars "eat" Mobil 1, but not any other oil? Why would this be?

 

[KHP]

Originally Posted By: Josh8519
So that means a thicker oil is even better for the 2008+ then right?

Also, what exactly causes oil consumption? For some reason a lot of Subaru owners claim their cars "eat" Mobil 1, but not any other oil? Why would this be?


I'm not sure if thicker is always better. It depends on the how the car is driven, environment, and also by the specific engine. Engines of the same make and model can be very different from one to another.

As for turbo EJ motors consuming Mobil 1 oils. I can confirm this in my engine. My EJ255 consumed 1Qt in ~7,500 mile OCI(M1 EP 5W30 SN and SM in my case). While consumption is non existent with PU 5w30 SN (My WRX loves PU 5/10w30 SN). I have no idea why this is the case other than maybe the M1 shearing out of spec to 5w20.

 

[Josh8519]

I haven't heard of oil consumption with the 0w-40 M1, so maybe you are correct about shearing causing it.

 

[05LGTLtd]

Originally Posted By: Josh8519
So that means a thicker oil is even better for the 2008+ then right?


The Oil "Cooler" also helps heat the oil to operating temp faster from cold start, so that has to be factored in to the equation. Constantly short tripping your car in sub freezing temps vs hard prolonged driving at high ambient temps: With oil cooler, the same oil might be just fine, without an oil cooler you probably want to tailor to the needs of the situation...

 

[CATERHAM]

Originally Posted By: 05LGTLtd
Originally Posted By: Josh8519
So that means a thicker oil is even better for the 2008+ then right?


The Oil "Cooler" also helps heat the oil to operating temp faster from cold start, so that has to be factored in to the equation. Constantly short tripping your car in sub freezing temps vs hard prolonged driving at high ambient temps: With oil cooler, the same oil might be just fine, without an oil cooler you probably want to tailor to the needs of the situation...

It is better referred to as an oil/coolant heat exchanger since main benefit is to bring the oil up to temperature quickly. It acts as an oil cooler when the oil temp's rise above the coolant temp's and you use a lot of WOT raising the oils temp's.

 

[thescreensavers]

Whats weird is that the Current Year STI's still retain this oil cooler/warmer.

For hot climates would it be beneficial to install a small oil cooler?. I guess one would need to get an oil temp gauge and see what temps they are hitting.

 

[CATERHAM]

Or first just install an oil pressure/temp' gauge to see if you even need an oil cooler.

 

[gregoron]

Originally Posted By: Josh8519
I haven't heard of oil consumption with the 0w-40 M1, so maybe you are correct about shearing causing it.


He said he was consuming M1 5W-30 not 0W-40, which he should be using for his engine. I don't think that oil shearing by itself results in oil consumption. Mechanical and oil weight-related factors come into play as well.

 

[Zako2]

Originally Posted By: DrDusty86
My roomate with the STI says he HATES mobil one in the 3 STIs he's had because they drink it like water he says a quart every 500-850 was the norm. He says he likes GC the best followed by T6. He has never done a uoa and his last one lost a ring land.
M1 flavors he has tried:
HM 10w40
TDT 5w40
EP 5w30
15w50


Mobil 1 0W40 is a different animal. Like the German Castrol, it's made to german car specs.

 

[Josh8519]

For some reason my mpg seems a little better on the 0w-40. I haven't changed my driving habits.

Just checked the oil level after 100 miles. Still full.

 

[aquariuscsm]

Originally Posted By: Zako2
Originally Posted By: DrDusty86
My roomate with the STI says he HATES mobil one in the 3 STIs he's had because they drink it like water he says a quart every 500-850 was the norm. He says he likes GC the best followed by T6. He has never done a uoa and his last one lost a ring land.
M1 flavors he has tried:
HM 10w40
TDT 5w40
EP 5w30
15w50


Mobil 1 0W40 is a different animal. Like the German Castrol, it's made to german car specs.


Hey Dusty,which M1 flavor did he say ran the best out of all the ones he tried?

 

[Josh8519]

Yeah, this is really weird. Here's my average mpg right now (I reset my trip counter when I changed to M1). this is with around 70% city driving. Now, I could RARELY even hit 25mpg with 100% highway driving when I had PU 5W-30.

Very weird, but I'm not complaining.

http://imgur.com/LqlcQJr.jpg

 

[Josh8519]

How long does it usually take for the oil to reach operating temp? Shortly after the coolant reaches operating temp?

 

[thescreensavers]

Went Auto Crossing this weekend, and talked to another guy with a Subaru. He owns his own shop..etc so I decided to ask him about the whole 5W-30 thing. He says he has been working on Subarus for 10 years and to Screw the EPA and he runs Castrol Syntec 5W40 with BG's MOA additive. He used to run MMO but changed to BG's MOA and has been running it since 2007ish

He told me just to put in 40wt and tell Subaru to take a hike.

M1 0W40 seems like a pretty good candidate if I buy at walmart like previous poster said would just say "Mobile Oil"

hmmmm

 

[Josh8519]

If this mobil 1 holds up great and protects my engine, it will be the best oil I have ever used.

My engine is much quieter, the car runs noticeably smoother, it accelerates better, and I get better MPG.

Seriously, this stuff is magical from all I experienced. I'm not imagining it either. My engine accelerates noticeably smoother, and I have more torque (proven by my latest dyno, and I didn't change anything besides the oil).

It's amazing. I'm currently sitting at 22.8mpg after almost 150 miles with 90% city driving. Previously, I'd be lucky to get 21mpg.

 

[CATERHAM]

So you're getting 9% better fuel economy with the heavier M1 0W-40 vs PU 5W-30?
I'm glad you're engine is running well but even Mobil wouldn't attribute your observations to their oil. If you switch back to PU at your next oil change, you'll probably see a further improvement in what you've noticed as your new engine accumulates more mileage.

 

[gregoron]

Josh8519, keep us posted on any oil consumption with M1 0W-40, if any. It would normally take around 500-1000 miles for the oil to get used to your engine. Just check oil levels every 500 miles and top up if necessary.