75W90 GL-5 LS In a transmission?

[sg1379]

Hello,

My Subaru (2012, 2.0) Impreza's manual transmission call for 75W90 GL-5 API oil and the manual does not provide any other info.

The dealer would use regular Castrol conventional oil, but I would like to get a synthetic oil for cold weather (-20C in February).

From my research, I only see advice to use Subaru Extra-S (which is discontinued) or Motul Gear 300, and I can only find it at 30$ per liter (quart) in Canada. I was thinking about getting this but I'm not sure.

Most synthetic gear oil has Limited Slip additives, does it affect the manual transmission? Should I absolutely get a non LS oil?

 

[ARCOgraphite]

Use the Subaru or whatever they like on the subie forums PM Bluesubie. There used to be a love of RL and amsoil mixture.

I haven't found a grpIII syn hypoid that I like.
Absolutely forget Mobil LS.

 

[RedOakRanch]

Subaru makes an extra m now that's basically a 75w85. In my area I can get delo syn 75w90 with no additive for $5.99/qt at Autozone. I use it in everything! The Dino version is $6.99...

 

[Rand]

walmart supertech 75w90 is ok

most syn are bad..have too many friction modifiers

redline 75w90NS
motul gear 300

I've run all 3 I mentioned.

ps subaru extra mt is spec'ed for 2014+ and is
an exotic 75w80 api gl-5

http://parts.subaru.com/p/Gear-Oil-Extra-MT-75W80/49506107/SOA748V0100.html

 

[MolaKule]

Originally Posted By: Rand
walmart supertech 75w90 is ok

most syn are bad..have too many friction modifiers

redline 75w90NS
motul gear 300

I've run all 3 I mentioned.

ps subaru extra mt is spec'ed for 2014+ and is
an exotic 75w80 api gl-5

http://parts.subaru.com/p/Gear-Oil-Extra-MT-75W80/49506107/SOA748V0100.html


The Extra MT is the one you should be using since most of these units have common sumps for the MT and diffy, so they have to have a GL-5 rating but still include the proper friction modifiers for the synchros.

Quote:
most syn are bad..have too many friction modifiers


Not so. In fact, most modern MT chemistry has a mix of synthetic base oils.

 

[sg1379]

Do you know where I can find that, most products suggested are only available in the US and has no equivalent in Canada. When I went to the dealership, they told me they had bulk Castrol conventional oil, and no synthetic.

My research only points me to Extra S, not Extra MT

 

[QuietPortage]

Extra-S is no longer available. Subaru of America now stocks Subaru 75w-90 High Performance Gear Oil for your application. It may be the same in Canada. I found that this new formula performed poorly when compared to the old Extra-S.

So, my recommendation is to locate a 75w-90 without limited slip additive. Synthetic or conventional are fine.

I preferred Mobil Delvac 1 and Motul Gear 300 in my 2013 Forester. You should be able to find them easily enough by searching for dealers on their respective websites.

 

[QuietPortage]

Here is some additional reading:

http://forums.nasioc.com/forums/showthread.php?t=2678891

I believe the part number for Subaru HPGO is SOA427V1700. Your Canadian dealership may or may not be able to order it, if you want to go that route.

 

[sg1379]

Thank you all for your answers, Motul Gear 300 seems to come back often, it is a good synthetic oil with no LS additive.

I managed to find it in Canada with free shipping on a motorcycle website!
https://www.canadasmotorcycle.ca/motul-gear-300-synthetic-oil.html

I will get:
3L of Motul Gear 300 for the gearbox (27$*3)
1L of MotoMaster Synthetic Gear Oil for the rear diff (15$) (cheapest syn I could find, the additives doesn't matter in the open rear diff)