Planning to do a full change of fluids on my car, an unmodified US-spec MY05 with roughly 83k miles. I acquired the car recently, and do not know when last the gearbox and diff oils were replaced. Looking around on the forums, there is quite a bit of conflicting information on which type of oil to use for the diff. The manual specifies a single-grade 90 weight oil, but I have not found anything of the sort on the shelves of the local auto-parts stores. What should I use?

 

You CAN use the Honda Hypoid 80w90. I'm a tech for Honda and this what goes in every customers S2000, never had an issue and never personally seen anything happen with this oil.

However, I've been using Amsoil 75w110 (the 75w90 from Amsoil is acceptable also) in mine for nearly 100k with zero complaints or faults, but I drive my car harder than the average cruiser, otherwise I'd stick with the Honda 80w90.

 

Billman recommends Mobil1 75W-90. Some prefer 75W-140.

 

Billman recommended that I use 75W-140 in the Stage 2 diff that he built for me.

 

Amsoil 75W-110 is my vote

 

i second this Amsoil FTW

 

Firstly, thank you all for your responses. Secondly, is it necessary to add any friction modifier to the Amsoil 75w-110?

 

No.
I'm another one using Amsoil 75w-110.

 

75w-140 recommended by puddymod. I use Amsoil.

 

In the event the photo does not show I use LE 1605.

http://i1154.photobucket.com/albums/...psdplv08na.jpg


-- Chuck