Comparing 3 oils for a 2011 WRX

[rationull]

I've used Subaru's branded 5w-30 oil in my 2011 WRX since it was new because I was able to get it for a really good price. However that deal is now gone, and the car is out of warranty, so there's no reason to keep using it (although the dealer price is still a couple bucks cheaper per quart than good synthetics are when not on sale). So I'm debating what to use. I'm not sure posting this is a good idea since there are many, many threads specifically on oil choices for the EJ25 turbo engines, but I'm weighing three options and wanted to get anyones opinion who might want to chime in with good information.

I'm not debating too much between 5w-30 and 0w-40. This is a spirited daily driver, not a track car, and I'm not convinced that the heavier oil trade-off is worth it when considering oil temperatures on normal driving patterns. However I'm not fully convinced.

What I'm really trying to choose between:

PU 5w-30: I have seen good UOAs with this oil in this engine, and it may be available in stores around here. Local availability would be the only advantage other than being an all around good oil. Leaning against this due to the other options, though.

Amsoil SS 5w-30 (or 0w-40): Either weight would be good. This is tempting because with discounts I think it could be about the same price as the (non-sale) PU and is probably a better oil.

Or:

Amsoil OE 5w-30: The budget Amsoil would be a really good deal with discounts. It doesn't get great press but the specs are decent. If the PU would be a good choice and this is basically equivalent but cheaper, it seems like it could be a good option.



I'm kind of leaning toward the Amsoil OE due to what I perceive to be an all around good deal for a good oil but most of the Amsoil reputation seems to be applied to SS and their other more expensive lines. Also if the argument for 0w-40 is compelling on a daily driver, then the SS would be an easy choice. I don't anticipate that argument being solved in this thread though

Thoughts?

 

[daves87rs]

Liking the PU currently in my car- has seen all different types of things this winter and has held up well, and still runs butter smooth.

 

[Kuato]

Partial to the Amsoil myself. The 0w40 is definitly worth a tryout.

Between SS and OE, could depend on your planned OCI. They are very similar,just more TBN in the SS. The OE should be good for at least 6k and probably longer.

 

[rationull]

I have only run 5k OCIs so far and wasn't intending to change that.

I think OE and XL are "the same" other than TBN, but I'm not sure that SS is the same thing.

 

[Kuato]

Originally Posted By: rationull
I have only run 5k OCIs so far and wasn't intending to change that.

I think OE and XL are "the same" other than TBN, but I'm not sure that SS is the same thing.


You're right, base oils are different it's the additive package that is similar.

I think that OE or XL would be more than adequate for a 5k OCI.

 

[Donald]

The PU is probably better oil than Amsoil OE. And cheaper. If your going to get Amsoil, get the top shelf Amsoil.

PP or PU will be excellent choices.

 

[demarpaint]

Originally Posted By: rationull
I've used Subaru's branded 5w-30 oil in my 2011 WRX since it was new because I was able to get it for a really good price. However that deal is now gone, and the car is out of warranty, so there's no reason to keep using it (although the dealer price is still a couple bucks cheaper per quart than good synthetics are when not on sale). So I'm debating what to use. I'm not sure posting this is a good idea since there are many, many threads specifically on oil choices for the EJ25 turbo engines, but I'm weighing three options and wanted to get anyones opinion who might want to chime in with good information.

I'm not debating too much between 5w-30 and 0w-40. This is a spirited daily driver, not a track car, and I'm not convinced that the heavier oil trade-off is worth it when considering oil temperatures on normal driving patterns. However I'm not fully convinced.

What I'm really trying to choose between:

PU 5w-30: I have seen good UOAs with this oil in this engine, and it may be available in stores around here. Local availability would be the only advantage other than being an all around good oil. Leaning against this due to the other options, though.

Amsoil SS 5w-30 (or 0w-40): Either weight would be good. This is tempting because with discounts I think it could be about the same price as the (non-sale) PU and is probably a better oil.

Or:

Amsoil OE 5w-30: The budget Amsoil would be a really good deal with discounts. It doesn't get great press but the specs are decent. If the PU would be a good choice and this is basically equivalent but cheaper, it seems like it could be a good option.



I'm kind of leaning toward the Amsoil OE due to what I perceive to be an all around good deal for a good oil but most of the Amsoil reputation seems to be applied to SS and their other more expensive lines. Also if the argument for 0w-40 is compelling on a daily driver, then the SS would be an easy choice. I don't anticipate that argument being solved in this thread though

Thoughts?


You mentioned PU 5W30. I paid under $28 for 5 qt jugs of PU shipped to my house, free of charge. Walmart offers free shipping on orders of $50 or more, two jugs and its shipped free. Not a bad deal if you like PU and don't feel like driving around to find or get it. You could buy a years supply in one shot and be done with it.

 

[Rand]

I'd go in a different direction

Rotella T6 5w40 is extremely popular in those engines..

Or maybe M1 0w40

 

[Padawan]

Originally Posted By: Rand
I'd go in a different direction

Rotella T6 5w40 is extremely popular in those engines..

Or maybe M1 0w40


I agree. Skip the 5W-30s in that engine.

 

[rationull]

I think Rotella is overkill in my application. It's just a daily driver and the Subaru 5w-30 has been OK (been a while since a UOA though). 0w-40 may protect better on long, hot drives but what I'm hung up on is I don't really know what the practical disadvantage of the thicker oil would be on short daily drives. If that's not a big deal then I'm tempted to go with one of the 0w-40 options (in which case the Amsoil and the PU are much closer in price).

 

[razel]

5k oil interval? You are overthinking it. Motor oils have been fantastic for at least 5 years now. Buy any SN oil of the weight you need/want. If you can't sleep at night get oil analysis every 1k. They're far cheaper to do now. NAPA has $15 kits.

 

[wemay]

Daily driver, no modifications to drive train, or track days...

5W-30
Mobil1
QSUD
Pennzoil Plat
Edge
SynPower

take your pick of any of these fantastic oils.

 

[6starprez]

I don't know if you spend any time on nasioc.com but the story goes energy conserving 5W-30 in those turbos shear to 20 weight. Then Boom! You'll see a lot of T6 and Mobil 1 0W-40 recommendations.

 

[rationull]

Yes, I've read a lot of that. The two UOAs I've done on Subaru's 5w-30 do not see them shearing to a 20 weight, but staying in the high 9s to mid 10s cSt at 100 deg C. And there are plenty of other 5w-30 UOAs around with the same result.

 

[rationull]

I wish this car had oil temp and/or pressure gauges to make it easier to know whether there'd be an advantage to the 40 wt. For now it seems like the PU 5w-30 will be the best bet.

 

[mjoekingz28]

I dont really like to veer from the owner's manual- so if it says 5w-30 then listen to wemay. I would also side with him if you just hit the go pedal in short bursts.

However,

If you keep it on boil for a while, the Rand and padawan as well as probably a whole website dedicated to the car will probably be 'best'.



I associate RT6 and Subaru turbos together- and I have never ridden in one nor used Rotella synthetic. I did ride in a Subaru, once I thin, and I did drive a diesel which probably had some 15w-40. I also put Rotella 3 in a dirtbike, but it did slip out of gear a time or two, so I doubt it is really best (more likely- barely adequate) for every vehicle made. Heck, there are probably pilots using it in prop aircraft- it has (or seemed to have) that kind of following.

 

[rationull]

I think the 30 weight is the right choice given my driving style -- most of my driving is highway with just short bursts of faster acceleration. I generally take it pretty easy in the course of normal driving.

The one thing that does give me pause is a steep grade on my commute that's a few miles long, although it's not like it requires a lot of throttle to maintain speed or even accelerate in 4th or 5th gear. Real full throttle still can't last for more than 5 or 10 seconds at legal speeds assuming you're in the right gear. Then there's also the theoretical long drives during the summer in 100+ degree heat with some hard acceleration interspersed throughout, but that's a 2-3 times a year thing for me.

Still, it seems like the thinner cold viscosity of the 30 weight is a good thing more often than not, given this car gets most of its miles on commute and errands.

 

[rationull]

Originally Posted By: mjoekingz28
I dont really like to veer from the owner's manual- so if it says 5w-30 then listen to wemay. I would also side with him if you just hit the go pedal in short bursts.


The OM does say 5w-30 and there is rich discussion around how valid this is given that Subaru has changed the requirements over the years while making perhaps fewer relevant changes to the engine over that time frame. However the oils have evolved at the same time, and they also moved to specifically require synthetic where before they seemed to allow conventional as well -- so there are confounding issues.

 

[BrocLuno]

In Kalifornia, the 40W will be no disadvantage at all. The heat of summer will bring the temps up and it will help if climbing passes or running freeways at 80, etc. (I-5...). There is a reason so many run T-6 in Subies

 

[rationull]

Originally Posted By: BrocLuno
In Kalifornia, the 40W will be no disadvantage at all. The heat of summer will bring the temps up and it will help if climbing passes or running freeways at 80, etc. (I-5...). There is a reason so many run T-6 in Subies

Even in my temperate region a year-round oil needs to be able to handle the freeway at 106 degrees as well as getting on the highway in the morning when it's 25-40 degrees. I'm not convinced that the improvement of the 40w on the high end fully cancels out the benefit of a good synthetic 30w on the low end in my case, and something closer to the colder case is proportionally much more common than the hot case for me.

As CATERHAM points out frequently in related threads there's really know way to know for a given situation without oil pressure and temperature monitoring.