What do you guys in colder temps use for rear diff oil? They give a few different options in the manual depending on what temperatures you will see. I want something that will be good year round. Or is the stock fill of 80W-90 good enough? Thanks!

 

I'd say just use stock requirement. Typically thats fine, unless you are driving through the north pole or the sahara dessert year round.

 

75-xxx synthetic like Mobil one
75-140 if you also go hot/ mountains/ tow