Subaru WRX 50-weight oil question

[dmhudson91]

Toying with the idea of running a synthetic 50-weight oil in the WRX for the upcoming Houston summer months.

I currently use Rotella T6 but haven't Autocrossed (or really beaten on the car) in the summer heat (new-to-me as of last May). The UOAs for T6 have been fantastic FWIW.

Car has 110k miles and consumes ~1 quart per 3000-4000 miles on Rotella.

 

[DustinAsh]

My brother runs delvac 1 5w40 in his StI & has had great results...

 

[gathermewool]

Why?

 

[CT8]

15w-50 Mobil 1 would be worth a try!

 

[Padawan]

Assuming you use a decent quality oil, it should be a fine choice. I personally stick with xW-40 HDEOs in ours, since they're readily available and inexpensive. This upcoming oil change will be Super Tech 15W-40.

 

[Padawan]

Originally Posted By: gathermewool
Why?


One could also ask, why not?

Bear in mind that Subaru themselves state:

If the vehicle is used in desert areas, in areas with very
high temperatures, or used for heavy-duty applications such as towing a trailer, use of oil with the following grade and viscosities is recommended.

API classification SL (or SJ): SAE viscosity No.: 30, 40, 10W-50, 20W-40, 20W-50

 

[aquariuscsm]

How about Castrol 5W50.

 

[dmhudson91]

Thanks for the recs guys! Will look into it. Just wanted to make sure I wasn't crazy running a 50-weight on a stock motor considering the climate and heavy use.

 

[dparm]

Originally Posted By: Padawan
Originally Posted By: gathermewool
Why?


One could also ask, why not?

Bear in mind that Subaru themselves state:

If the vehicle is used in desert areas, in areas with very
high temperatures, or used for heavy-duty applications such as towing a trailer, use of oil with the following grade and viscosities is recommended.

API classification SL (or SJ): SAE viscosity No.: 30, 40, 10W-50, 20W-40, 20W-50



As others have said on here before, those statements & recommendations still exist due to cultural norms/expectations in certain regions, not because they're truly necessary.

 

[RedOakRanch]

Sustina 5w50 and do a UOA after 5k or so.

 

[901Memphis]

The HTHSV of T6 is more than sufficient unless your oil temperatures are 300F.

 

[Padawan]

Originally Posted By: dmhudson91
Just wanted to make sure I wasn't crazy running a 50-weight on a stock motor considering the climate and heavy use.


You're not, but that won't stop some folks who have no experience with these engines from trying to convince you you are.

 

[Padawan]

Originally Posted By: dparm
As others have said on here before, those statements & recommendations still exist due to cultural norms/expectations in certain regions, not because they're truly necessary.


The mere fact that others here have said something doesn't necessarily make it true.

That statement comes from the US-spec owner's manual, and could easily have been ommited by SOA if they didn't believe it had merit.

 

[umungus1122]

You could, but as "The UOAs for T6 have been fantastic", why change? Are you planning on getting the oil hotter than previously?

 

[dmhudson91]

Yes absolutely planning on getting the oil hotter. Have only done two UOAs. one on oil used from October-December, and the second was used from December to February/March. I bought the car the end of last May and babied it as I fixed various issues and learned to drive stick. I've only been riding her hard since last fall and the first autocross was done last October.

So with all that said, running the car hard through the summer with once or twice monthly autocrosses has me thinking about a 50-weight.

 

[Eddie]

I would ask the Subaru groups that race them rather than self appointed experts who lurk here. Ed

 

[dmhudson91]

But isn't everyone on the internet an expert?!

 

[bluesubie]

Originally Posted By: dmhudson91
But isn't everyone on the internet an expert?!

Yes!!

Judging by looking at uoa's on WRX's for the last 13 years, on cars with all types of mods producing varying amounts of horsepower (as well as feedback from engine builders, racers, etc.), I don't think you need to go any thicker than a 40 grade unless you have an open class rally car, or a built motor with clearances that need a 50 grade.

Although if a 50 grade floats your boat, go right ahead if it makes you sleep better at night. People here and on nasioc know I'm a huge advocate of running thicker oils (especially in the EJ WRX's) but even I think a 50 grade is overkill unless you have an aforementioned rally car.

 

[CT8]

Originally Posted By: dmhudson91
Thanks for the recs guys! Will look into it. Just wanted to make sure I wasn't crazy running a 50-weight on a stock motor considering the climate and heavy use.
As usual let the engine temps warm up before WOT !!!

 

[bluesubie]

Here's a post about Mobil 1 15W50 in a Legacy GT:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1656589

Quote:
I tried out Mobil One 15w50 to see how the car would run with it. It was run during the hottest months of the year, but got some starts down around 40 degrees.....never failed to start easy, every time, and the car seemed to like it when being driven hard. Turbo spool seemed a bit slower though.

I'm going to stick with 5w30, 0w30, and 5w40 oils from here on out unless I start tuning and running during hot months, at which time I might use a 10w40 or similar. Just wanted to try out what is typically considered a "very thick" oil.