[hcd]

Does anyone know the viscosity number for the differential oil the factory uses? I live in rural Alaska and operate our new 2013 2.5i Outback CVT under extreme conditions (low temps and very short drives.) According to the warranty and maintenance guide, at 15,000 miles I'll need to replace the front and rear with 75w-90.

There are plenty of threads about the low mpg these Outbacks are getting in cold weather. It's occurred to me that the factory might not be using 75w-90, but rather a straight 90 as is called for in cars operated in temperatures above 35 or so.

 

[G-Omaha]

but rather a straight 90 as is called for in cars operated in temperatures above 35 or so.

Live in the central part of the USA. Where is this 90 called for?

 

[SubyTechJoe]

As far as I know Subaru Uses Extra S which is 75w90 in all new cars

 

[hcd]

Live in the central part of the USA. Where is this 90 called for?

It's in the manual, section 12.7 and there's a diagram of a thermometer. It looks like in regions that never have temperatures below 35 f, either a SAE viscosity of 90 and API classification GL-5 or the 75w-90 is called for in the front and rear differentials.

 

[AWDFTW]

Factory is 75w90.

 

[OutbackUFO]

I changed the diff oils in both our Subies with Redline 75W90 and all is well..

 

[147_Grain]

You definitely want the 75W-90 and for cold temperatures the synthetic version is preferred.

Amsoil Severe Gear 75W-90 / Redline 75W-90 / Mobil 1 Synthetic 75W-90.

 

[hcd]

You definitely want the 75W-90 and for cold temperatures the synthetic version is preferred.

Amsoil Severe Gear 75W-90 / Redline 75W-90 / Mobil 1 Synthetic 75W-90.

I agree, thanks. I'm looking at the Amsoil and Mobil 1. I wander if the Extra S that comes stock is synthetic. I've seen different opinions.

 

[147_Grain]

My dealer mentioned the factory fill is a dino gear lube.

Subaru dealer also drained the front and rear differentials at 5K and the Service Manager was called over to see all the metal flakes in the drain pan. Technician was joking that he had struck gold. Labor was also $28.50 per differential and I provided the Amsoil Severe Gear 75W-90 synthetic oil.

For best results, I suggest you stick with Amsoil Severe Gear 75W-90 / Redline 75W-90 / Mobil 1 Synthetic 75W-90.