Mazda 2015 CX 5 AWD Diff and Transfer case... SG 1 or 80w90?

[fintip]

This is my first time doing diff fluid. I live in the mountains, bought it at 95k miles, do a lot of long drives and have put close to 30k miles in 1.5 years here in Colorado.

I bought mobile 1 75w90 sy thetic Gear lubricant LS API GL-5.

Official spec seems to list 80w90.

However, ChatGPT is _insisting_ that later service tech internal memos or service bulletins retroactively updated this to suggest SG1 for my vehicle as 80w90 was found to shorten life on these and that issues happen.

I'm fine shelling out for SG1 If I really should but I'm just lost.

Anyone able to give guidance?

 

[zfasts03]

I have HPL diff life 75w-90 in the 2 holes of 20 CX5. Seems to be working well.

 

[Propflux01]

I have amsoil 75w-85 severe gear in mine. Just changed them last week. No issues so far.