Turbo subaru: what oil?

2006 turbo Subaru Baja. Do for an oil change. It makes good oil pressure on no name 5W30 according to the mechanical gauge. I'm debating what type of oil to grab at Walmart tonight while I'm picking up my medications. My gut says to put Rotella t15w40 in it like I do with all my other vehicles because of the higher sink and because it keeps it the same across the entire fleet. The other part of my brain says put 5w 30 in it like the oil cap calls for maybe even stepping up to Walmart brand synthetic as the thing has over 200,000 miles on it. What do you all say?

I always used synthetic in the weight recommended, previously castrol, currently using costco brand synthetic. 

I would go for an ordinary full-synthetic street-performance oil, a high-zinc oil might foul emissions bits and the higher zinc isn't helpful for a stock street engine. A slight viscosity bump could be a good idea for an old engine, maybe up to 5w40, or 10W40 if it doesn't see winter temps.

i'd use whatever spec in whatever weight sube recommends via the owners manual.

as far as brand and type, i'm a big fan of Castrol Edge High Mileage for everything except the Escape (it isn't a high mileage car yet).

when/if bobzilla chimes in, i'd probably follow his recommendation.

200k+ on a turbo Subaru....I'd keep doing what you're doing. 

Are you putting it on a track and running 30 minute sessions all day? Run a 0 or 5w40 synthetic of whatever brand you feel like. Daily driver? Grab Walmart synthetic oil and be done. Don't cheap out on the filter. 
 

seriously though, I've said this before but any modern oil that meets the manufacturers requirements will be fine. And that means it's pretty much any oil not bought from the dollar store for $1.25/qt. 

Use a synthetic in the correct viscosity. I've heard that going heavier can cause issues.

The debate around using Rotella in the Subie engines is intense, divisive and borders on the insane. Woth checking out if you get bored.

In reply to Brett_Murphy (Agent of Chaos) :

And it could all be answered by facts if they tested correctly 

It looks like I'm grabbing Walmart synthetic tonight while I'm there. I run Rotel in all the rest of my junk due to Flat tappet cams. Thanks everybody!

Note that the Rotella T6 usually used in turbo Subarus is the 5W-40, not 15W-40.  I'm of the opinion that unless specifically called for, there's really no reason to ever use 15W-40 in anything today.  Especially in a turbo car where you might spool the turbo some while it's cool.  A 15W oil is just going to get you more startup wear than a 5w or 0w--and startup is wear most street engines get most of their wear.... why would you want to do that to an engine?

The higher zinc in T6 can't be good for catalytic converters, which is why it doesn't meet the specs, regardless of the weight.  But tons of turbo subaru owners use it exclusively...

I ran Mobil11 5W-30 in my WRX and changed it at the specified 7,500 intervals.  Met the requirements Subaru specified, and it was under warranty.  The Subaru forums were full of people complaining that it was terrible oil that would shear in no time, but I did oil analysis at every oil change and never saw any issue.  Met the specified viscosity every time. Never a problem with the engine when the car was totaled at 90k miles.

In reply to Berck :

for your 40 weight needs, M1 makes an oil for the Corvettes spec'd at a 0W40. Works really well in the Rio even though it's two grades higher than the OE spec'd. Then again, the rio has rings that consider the idea of keep oil where it needs to be at high rpm and has the go pedal matted to the carpet for such long periods of time on track that it's surprising that it doesn't "gain" oil from the fuel dilution. 

Something, something....  subaru engine is gonna break before you need to change it... something, something.

Hope not anyway!

To be clear, this is a joke!  #propogationofstereotypes.

I used to run Shell Rotella synthetic T6 5w40 in both my 2002 and 2009 WRX. Never had engine issues with either one, and never burned a drop, either. Highly recommended for the old EJ20/EJ25.