[sti* fan]

look for Subaru "extra S" fluid its what the car originally comes with from the factory..

its very hard to get in quart bottles I got mine here

Fred Beans Parts Messages

Check with them for ETA

[severe]

id like to point out that GR 08 sti manual recommends same oil for tranny and differential.

also doing some reading apparently they use different types of differentials from previous years.

ill be putting Subaru Extra S in both.

[07stiman]

What about pennzoil for trans n rear diff i really need some advise thanks

[CygnusPerformance]

Originally Posted by severe

id like to point out that GR 08 sti manual recommends same oil for tranny and differential.

also doing some reading apparently they use different types of differentials from previous years.

ill be putting Subaru Extra S in both.

The factory fill for the tranny and diff on 07+ cars is Subaru Go Extra-S. It is a highly refined mineral oil made by Shell in Japan for Subaru. Prior to the 2007 model year STIs came with a clutch style rear limited slip differential which required an oil with friction modifiers in it in order to function properly. For 04-06 models you should use Subaru LSD Oil. Newer models have a torsen style diff which uses gears instead of clutches to function. Gear style diffs do not require friction modifiers, so you can use any quality 75W-90 for them. I personally use Go Extra-S for both my tranny and diff.

[sti* fan]

Originally Posted by CygnusPerformance

The factory fill for the tranny and diff on 07+ cars is Subaru Go Extra-S. It is a highly refined mineral oil made by Shell in Japan for Subaru. Prior to the 2007 model year STIs came with a clutch style rear limited slip differential which required an oil with friction modifiers in it in order to function properly. For 04-06 models you should use Subaru LSD Oil. Newer models have a torsen style diff which uses gears instead of clutches to function. Gear style diffs do not require friction modifiers, so you can use any quality 75W-90 for them. I personally use Go Extra-S for both my tranny and diff.

were you saying the "2007" sti's and newer use extra-s in both the front and rear diffs?

I have a 2007 and I recently did my tranny, front diff, and rear diff.

for the front diff and tranny i used "extra S"

i used Lsd gear oil "motul 90 PA Limited-slip diff" fluid for the rear.

Is this correct what i got from your post was 2007 and up use the same fluids in both diffs. thanks.

[CygnusPerformance]

Originally Posted by sti* fan

were you saying the "2007" sti's and newer use extra-s in both the front and rear diffs?

I have a 2007 and I recently did my tranny, front diff, and rear diff.

for the front diff and tranny i used "extra S"

i used Lsd gear oil "motul 90 PA Limited-slip diff" fluid for the rear.

Is this correct what i got from your post was 2007 and up use the same fluids in both diffs. thanks.

Yes that is correct, the 2007 model uses a Torsen diff which does not use clutches and therefore does not require friction modifiers. Friction modifiers are what make limited slip diff specific oil different. Go Extra-S is the factory fill for your rear diff. That said, you should be fine. Torsen diffs are not picky at all. As long as the weight of the oil you used is 75W 90 or similar you'll be okay.

[sti* fan]

Originally Posted by CygnusPerformance

Yes that is correct, the 2007 model uses a Torsen diff which does not use clutches and therefore does not require friction modifiers. Friction modifiers are what make LSD specific oil different. Go Extra-S is the factory fill for your rear diff. That said, you should be fine. Torsen diffs are not picky at all. As long as the weight of the oil you used is 75W 90 or similar you'll be okay.

this is the first time ive read about my 07 having a torsen style rear diff and ive read LOTS of diff/tranny fluid threads..

for the rear im not sure if i have the appropriate fluid. you mentioned 75-90 i have pa-90(lsd gear oil) in the rear diff right now. Is the fluid im running ok??

90 PA Limited-Slip Differential

[CygnusPerformance]

Originally Posted by sti* fan

this is the first time ive read about my 07 having a torsen style rear diff and ive read LOTS of diff/tranny fluid threads..

for the rear im not sure if i have the appropriate fluid. you mentioned 75-90 i have pa-90(lsd gear oil) in the rear diff right now. Is the fluid im running ok??

90 PA Limited-Slip Differential

It's funny, a lot of Subaru dealerships don't even know. My best guess is that you are probably okay, but if you want a definite answer you might want to contact Torsen directly about this. Here is a link to their contact page It's been a long time since I've had to contact them about anything, but when I did have to contact them they were quite helpful.

Like I said, I'm pretty sure you will be fine. I know a lot of people put Subaru's LSD Oil in the 07s by mistake and I've never heard of any problems.

[sti* fan]

Originally Posted by CygnusPerformance

It's funny, a lot of Subaru dealerships don't even know. My best guess is that you are probably okay, but if you want a definite answer you might want to contact Torsen directly about this. Here is a link to their contact page It's been a long time since I've had to contact them about anything, but when I did have to contact them they were quite helpful.

Like I said, I'm pretty sure you will be fine. I know a lot of people put Subaru's LSD Oil in the 07s by mistake and I've never heard of any problems.

Ok so I see both types of fluid have the same protection grade rating(gl-4 and gl-5). just based on my observations when swapping the oem fluid to the motul the rear diff got alot quieter especially in tight turns zero noise at all compared to the original fluid.

[Deuce Cam]

Cygnus is correct. The 07+ sti's use the same fluid in the transmission and rear differential. It's mentioned in a few other threads but is often overlooked.