Anyone have info on Mazda SG1 gear oil options?

[ckarpson]

Hey everyone new member here. So heres my situation. My neighbor has a 2020 mx5 with lsd and i usually do all his work on his cars and he asked me to get him fluid to do some maintenance on his car for him. i was looking up on alldata and Mazda says to use long life gear oil SG1 for the rear diff which says on the bottle online 75w85 GL4 , but does not list an alternative. I wanted to know if anyone has more info on this fluid and would it be safe to use a 75w90 say Valvoline synthetic or Mobil 1 as they are both locally available. but to my knowledge diffs would require a GL5 for hypoid gears.

 

[pbm]

I replaced the OE rear differential oil with Royal Purple Maxgear 75w90 (which claims to be suitable for both GL-4 and GL-5) in my daughters 2021 CX-30 with the same engine as your neighbors. It's running fine. Unfortunately, I can't change the front transfer case fluid because Mazda blocked the fill plug on the CX-30.