Oil suggestion - 08 Subaru Legacy GT

[JoeFromPA]

Hi all,

Wife and I just picked up an 08 Legacy GT 5-speed (that's the 2.5 liter turbo engine, just in case you didn't know...)

Wife's car but I'll be enjoying it as well

Going to wait to 3k to do my first oil change, but already thinking about it. I'd like to switch to a good, but inexpensive synthetic.

Why? Well, Subaru changed their oil-interval recommendations to 3750 miles for the turbo engines (regardless of conditions). I'd like to have my bases covered if something goes wrong, and have lots of records and receipts.

I'm thinking about running Pennzoil Platinum 5w30 or Rotella T Synth 5w40. I'd try german castrol, but I've never even seen it before and there are few autozones around me...

I was wondering if anyone could give me any recommendations, comments, feedback, etc. on this giving my short intended intervals.

Thanks,

Joe

P.s. With the short intervals, I still want to run synthetic to help minimize long-term wear and give me peace of mind when I'm pushing her hard....

 

[tsmay51]

Bang for buck I don't know if you can beat pennzoil platinum. I would just make sure I bought the proper weight and put it in there with no worries. Others on the site have said that the 0w30 syntec is the german castrol. To be honest, I have no idea if it is or was at one time. Someone that knows please chime in here. Again, I don't think you could go wrong with pennzoil platinum.

 

[Veggieguy]

I'm currently running German Castrol (0w-30 Syntec) in my STI. My first UOA goes in the mail Monday.

If the results aren't excellent I'll probably try the RLI 5W40 HD.

I wouldn't hesitate to run PP, but I would probably try the 5w-40 Euro (if you can find it) or the 10w-40.

Rotella T Synthetic 5W-40 is another oil I would definitely try.

Since I don't have any evidence of my own yet, I can only say what I am considering trying if my UOA comes up short. All of these choices should be overkill for short OCIs.

 

[Ed_T]

For a 3,750 OCI you can probably safely use dino. That's what your OCI is designed around.

With the excellent cooling Subaru provides on your turbo setup, you'll probaby find an oil analysis revealing your dino in great shape at 3,750.

A 10W-30 would fit the bill nicely, being more shear-stable in general.

 

[bluesubie]

Nice car.

I would say conventional 10W30 or whatever synthetic 10W30 is on sale. Can you get Rotella 10W30?

-Dennis

 

[JoeFromPA]

Hi Bluesubie -

Thanks!

I'd use conventional but I'd like the "cooking" protection of synthetic as well as the greater stability of a 5w30 than 10w30 dino (I'd prefer to use a 0w or 5w for better cold start lubrication).

I can get Rotella T 5w40 synthetic for less than $3 a quart; any reason to use conventional instead?

Any reason you guys are recommending a 10w30 instead of a 5w40 for this turbo engine?

Joe

 

[bluesubie]

Is RTS 5W40 SM rated?

Here's a PP 5W30 UOA on an STI.

-Dennis

 

[SubLGT]

Originally Posted By: JoeFromPA
.......Any reason you guys are recommending a 10w30 instead of a 5w40 for this turbo engine?

Joe


For a stock motor, under average driving conditions, stick with a 5W30 or 10W30. If you are going to do road coarse races, then consider a 5W40. Better yet, if you want your choices to be guided by data, instead of opinions, start doing UOAs with Dyson.

 

[JoeFromPA]

Bluesubie - Interesting analysis....German Castrol did very nicely in that engine, and I'm a big fan of it's great flow characteristics when cold and thicker operating temp viscosity...

I'd definitely go with it, except it's so darn hard to find. Autozone the only place that carries it? How in the world do no online stores carry this oil?

SubLGT - What's the fun in going with data instead of opinion? That takes all the guesswork out of it. Way to ruin my fun.

 

[bluesubie]

GC is SL rated so you wouldn't be following the manual. Or does it say SL is ok "if you can't find SM"?

-Dennis

 

[gtx510]

Isn't the newer M07-M08 GC now SM? or SM/SL?
I'd check the bottle but I only have old stuff laying around.

 

[SubLGT]

Originally Posted By: JoeFromPA
..........SubLGT - What's the fun in going with data instead of opinion? That takes all the guesswork out of it. Way to ruin my fun.





You'll have fun with Terry Dyson too. When I asked him about a 40 weight oil for my "normally driven" unmodified '05 Legacy GT, he replied there would be no benefit. I suggest you do at least one UOA with him on the '08 Legacy, to make sure you don't have a fuel dilution problem. The '05 LGTs seem to be prone to fuel dilution and injector defects, and I'm not sure if this has carried over to the '08. Maybe not, as Subaru has done a redesign of the fuel rail and injectors.

 

[edhackett]

I just posted the UOA from my 2008 LGT using Rotella T 10W-30 for 3750 miles. It looks pretty decent. The Rotella was recommended by Terry over GC to deal with fuel dilution issues in my WRX.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1134771#Post1134771

Ed