I'm curious why so many folks are running 75w90 fluids in their differential as opposed to the 80w90 that Nissan recommends...what are the pros of this? BTW, Amsoil is one of the few that carry this weight (80w90) in a fully synthetic that I've seen.

|dg

 

because 75w90 is more accessible....thats my guess as to the reason. I've used both, and now actually use 80w140....none have made any significant difference whatsoever

 

75w90 also works well during the colder days.. it's not as thick as 80w90..

80w140 is a large span, but since most diff oils are synthetic, it's not going to be "cycled and burned up" as conventional gear oil..

I dont think you need to use w140 unless you plan to drift or track the car.

 

+1 no real differance but availability

 

Most importantly make sure it's GL 5.

Respect
JET

 

xenonk - agreed it is a huge span. I was trying to overcome a seperate issue I had, and it was one of those "what the hell let's try it" moments.

 

Thanks for the replies. I'm going with Amsoil 80w90 GL-5 in the diff. and their 75w90 GL-4 MTF in the tranny.

|dg

 

I'm currently running redline in the tranny, any comments on which is better Amsoil vs. Redline. I know everyone has their own personal oil preference but which one is really better for the tranny.

 

having used them all in a variety of cars, it makes absolutely zero difference for all practical purposes. So long as you stick to a reputable brand, you'll be in good shape.

 

Thanks!