I've got a 1994 4WD 4Runner and I'm looking to change my rear diff fluid. My manual says to use SAE 90 GL-5 if above 0 degrees f and SAE 80w or 80w-90 GL-5 if below 0 degrees f. I'm going be above 0 degrees f for the foreseeable future but I can't seem to find SAE 90 GL-5 anywhere. The stores here (Santa Fe) only sell SAE 80w-90 GL-5. Is this okay to use?

 

That will be fine, it's what I run.

 

80w-90 will be fine. i run it, but i also see 10 to 20 days with below zero temps per year (we've had 3 nights that have reached -20*F so far this winter).