06-07 Subaru 2.5L N/A - AWD Manual opinions

[AnGeL]

Hi!

I've just bought a new Subaru Impreza 2.5i Wagon manual and I need your advise of a "good" and not too expensive oil to put in the following:

Engine:
It's a 2.5L BOXER N/A motor with hydrolic actuated valve lift (EJ25 i-AVLS) and I want to be able to do 10000km per change. Subaru recommand generic 5W-30 changed at every 6000km. Some things to consider also:

1. Being a BOXER engine (piston travel horizontaly), which oil will best protect my piston ring?

2. The valve lift system is oil hydrolic activated so oil pumpability and fluidity is important in both head.

3. Being N/A engine (vs most Subaru are turbo) extreme heat protection is not a must in my case.

I've already made my first oil change with Mobil1 5W-30 but what do you think?

Lots of people in the Subaru world put Motul 8100 X-cess 5W40... is it good oil for me? It's also much more expensive than M1.



Tranny and transfert case: the famous Subaru AWD is composed of a compact viscous coupler embedded into the manual transmission case. Subaru recommand 75W-90 API GL-5 oil in there and changed at every 72000km - 45000mi.

Rear diff: It's a standard open diff; Subaru recommand 75W-90 API GL-5 oil changed at every 72000km - 45000mi.

Was thinking to put Mobil 1 Synthetic Gear Lube
LS 75W-90 in both tranny and rear diff (at least tranny)... any opinion?


My previous car was a Nissan Sentra SE-R Spec V and it was babysit with Mobil1 5W-30 and RedLine MTL/MT-90 all the time.

Consider also I'm in Canada and the car run all year... outside temperature will goes from -30C to +40C in extreme condition.


Any opinions welcome!

 

[Thatwouldbegreat]

Pick a good 5W-30 SM rated oil. Every 10K km is fine.

[ I like synthetic but any name brand SM rated 5W-30 oil is good. ]

Subaru oil filter or Purolator PureOne work well.

After the first 30 to 40K km change the tranny and rear diff fluids.

Or chane the tranny to Redline before winter.
Transmission Redline 75W-90NS every 80K km

Rear Diff Redline 75W-90 every 80K km

 

[mitchcoyote]

What you are doing now is a good plan....

 

[AnGeL]

Quote:

---

Transmission Redline 75W-90NS every 80K km

Rear Diff Redline 75W-90 every 80K km

---

Hum... did you misconfuse each other?

The RedLine 75W90 NS say it does NOT contain the friction modifier for limited-slip but because my tranny include the viscous coupler don't I NEED it?
http://www.redlineoil.com/products_gearl...mp;categoryID=6


And the 75W90 DO HAVE the friction modifier but in a regular open diff I won't need them right?
http://www.redlineoil.com/products_gearl...mp;categoryID=6



And for the engine, well if you think a "normal" oil is good enough for a Boxer engine regarding piston ring wear, well I will stick with Mobil1 5W-30. I was tend to use 10W-30 (at least in summer)... maybe next summer when my engine gonna have more mileage (right now only 5000km).

 

[Thatwouldbegreat]

I double checked with Dave at Redline Oil and you need:

Redline Oil 75W-90 NS for the manual transaxle

Redline Oil 75W-90 for the rear differential

Mobil 1 5W-30 would be fine. Mobil 1 0W-40 would also be fine for extreme temperature range.

Any of the name brand synthetics in 5W-30 whould be fine...especially if you can find them on sale like we have seen in the US in recent months.

Redline 5W-30 would be an outstanding oil in that engine, based on my experience. I'd change every 12km while in warranty.

Amsoil also has some very good oils , especially for after warranty if you want to go for longer intervals.

As you can tell I really like Redline products and have had great results with them.

 

[Titan]

I have two NA 2.5L Subaru engines, one a 2006, the other a 2007. Used Oil Analysis suggests that the SM-rated 5-30 oils that I used do fine. I even used 3 quarts of Exxon Superflow 5-20 with one quart of Delo 15-40 (I simply had to find a use for these oils, as I no longer had a Honda engine that specifies 5-20, and I no longer used the Delo 15-40 in my motorcycle...so, I mixed them), and the wear numbers were nothing but boringly low.

However, I get very good prices on Pennzoil Platinum 5-30, the UOA's are very good at 7500 miles, so, that is what I use. I do have synthetics in the front Transfer case and rear differential...from Specialty Formulations (they aren't currently open for sales, though), and I get in the lower to mid 30 mpg going 65 mph with the A/C on. So, I'm happy.

 

[Titan]

OOPS! I forgot, these two are automatics. I had a Saab 9-2X manual (and Impreza wagon), and I would get upper 30's in mpg at 65 mph. I had Specialty Formulations fluid in that gearbox, just like in my differential/transfer case.

 

[SubLGT]

Quote:

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......The RedLine 75W90 NS say it does NOT contain the friction modifier for limited-slip but because my tranny include the viscous coupler don't I NEED it?

And the 75W90 DO HAVE the friction modifier but in a regular open diff I won't need them right?

---

No limited slip friction modifiers are needed for the center differential, because it is a sealed unit, with its own internal fluid.

You do not need really need limited slip friction modifier in the open rear diff, but I think Redline recommends it because it may have other benefits (better mileage? less wear?)

 

[SubLGT]

Quote:

---

Was thinking to put Mobil 1 Synthetic Gear Lube
LS 75W-90 in both tranny and rear diff (at least tranny)... any opinion?.......Any opinions welcome!

---

Subaru manual transmission syncros are sensitive to fluids, and I don't think there are many good reports about M1 in the tranny, but it does work fine in the rear diff. For the transmission, you might want to consider Silkolene Silktran SYN5. I use the Specialty Formulations lube in my trans with good results, but SF seems to be on extended hiatus.

 

[Thatwouldbegreat]

Quote:

---

Quote:

---

Was thinking to put Mobil 1 Synthetic Gear Lube
LS 75W-90 in both tranny and rear diff (at least tranny)... any opinion?.......Any opinions welcome!

---

Subaru manual transmission syncros are sensitive to fluids, and I don't think there are many good reports about M1 in the tranny, but it does work fine in the rear diff. For the transmission, you might want to consider Silkolene Silktran SYN5. I use the Specialty Formulations lube in my trans with good results, but SF seems to be on extended hiatus.

---

I've used SF in our 2005 Outback and I like it!

I've used Redline 75W-90NS in lots of Subaru 5 speeds and it works great.

I also used Amsoil SVG 75W-90 in another one of our 2005 Outbacks and it also seemd fine.

Too bad SF is still not back!

 

[Steelhead]

the best value and quality in Canada Esso XD3 0w30

http://www.esso.ca/Canada-English/Files/Products_Lubes/IOCAENCVLESEsso_Xd-3_extra.pdf

Esso Gear Oil GX Extra is an API GL-6
quality oil specifically designed for severe
service with shock loading
Esso Gear Oil GX Extra is a premium
multi-service, extreme pressure, sulphurphosphorus
type gear oil recommended
for the high performance requirements of
API service classification GL-5 and GL-6.
A synthetic blended product available in
75W-90, and 80W-140 grades
http://www.imperialoil.ca/Canada-English/Files/Products_Lubes/IOCAENCVLESEsso_GO_GX_EX.pdf

 

[sprintman]

Dave told me to use 75W90NS in the manual trans and 75W90 in the diff. D4ATF in the p/s as well. Works brilliantly

 

[Dominic]

I too have a new 2007 Subaru 2.5i... the oil I use (Synpower 5W30) seems to be working well. So far my best is 29mpg, but I was doing 80 with the a/c on not 65mph.

 

[AnGeL]

SubLGT: Are you sure the central transfert case is into a sealed unit? Maybe on an automatic tranny but on the manual, I think the tranny and the central viscous coupler share the same oil.

If the central viscous coupler is sealed, there should be a way to change is own fluid too?


Steelhead: Hum... that Esso XD3 looks very good for use in the engine. Looks similar (if not the same) of the Mobil1 Delvac. I will try this one for my winter oil change in 0W-30 (only the 0W-30 and 0W-40 are PAO according to paper).


As the the Esso Gear Oil GX, I'm still not sure for a Subaru manual tranny if the central viscous coupler share the same oil. Specs paper say:
"Esso Gear Oil GX Extra 75W-90 is suitable as an
all-season lubricant for manual transmissions and
differentials in most passenger car and light duty
vehicles - including Ford high off-set hypoid
gears. The exceptions include those differentials
which require limited slip performance for which
Esso Gear Oil LS 80W-90 is recommended and
manual transmissions and transaxles for which
specific OEM or API service GL-4 lubricants are
specified."


Still, like the Redline, most people seems to recommend the Redline 75W-90NS "no slip" version for the manual tranny/viscous coupler so the Esso GX Extra 75W-90 might be good for me.

 

[meep]

I did 10,000 mile oci in our 1997 2.2L legacy, 10/30 M1, and it loved it. It hated fram oil filters on startup. at 100,000, valvetrain had zero visible wear, tolerances all in spec.

synth gear oil front/rear. Stick feel varied with type of synth gear oil.

Mike

 

[oilyriser]

I'm getting 32 mpg on the highway now, in a '01 Legacy. 5w20 oil, extended front air dam, well worn 205/70/15 tires. Amsoil s2k 75w90 in both diffs. Your car should get even better fuel economy from the adjustable valve timing, and slower rpm on the highway.

note: if you drive only short trips, 10,000 km will likely cause sludge.

Mobil 1 ATF cured the slow shifting into D problem during -25C weather. It should also reduce drag during warmup, for more gas savings.

Next winter, M1 0w20 might join the team.

 

[SubLGT]

Quote:

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SubLGT: Are you sure the central transfert case is into a sealed unit? Maybe on an automatic tranny but on the manual, I think the tranny and the central viscous coupler share the same oil........

---

The viscous coupler (center differential) inside the manual trans is a sealed unit, and contains a viscous, silicone based fluid. The external gears associated with the center diff are lubricated by the trans oil.

 

[AnGeL]

Ah really interesting!

Do I need to change this central diff silicole oil at some point?


And now I understand why a "general" GL5 oil without friction modifier can be put into the tranny.

For the Redline combo (75W90NS tranny and 75W90 in rear diff) that would make sense for a WRX because it as a viscous LSD on the rear axle, throught the need for friction modifier in the oil in there.

But my 2.5i have a rear regular open diff so just the 75W90NS would make more sense to me.

I'll see for the RedLine oil or something similar on my next tranny/rear diff change

 

[Dominic]

the central diff silicone system is SEALED and you change the UNIT if it fails to produce AWD. It should last at least 150000+ miles maint. free

the *viscous* wrx rear works the same way and also does not need any limited slip additive or anything. That is PURELY for clutch type differentials.