Anyone have info on Mazda SG1 gear oil options?

[ckarpson]

sorry posted this in the wrong section, ill repost in correct section

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.

 

[drtyler]

Just buy the Mazda fluid (which is pricey) unless you can get definite answer on why they spec 75W-85 GL-4. If you cannot, might be best to leave it alone.

The GL-4 could be due to yellow metals in the diff, in which case some GL-5 fluid could harm them. Many modern GL-5 formulations do not harm yellow metals.

 

[ckarpson]

well the only issue was that 2 dealers told him it is currently unobtainable at the moment.

 

[ARCOgraphite]

I would be more concerned about any required LSD additive.

That Gl-4 spec seems very odd - more like a MT spec than a diff spec.

I am going to check Amsoil rec's - right now

AMSoil recs severe gear GL-5/GL-4 75w90 for your vehicle. I would pick a this or Valvoline or Pennzoil 75W90.
Then dope with the Mazda LSD additive - if required - or pick a LSD rear member fluid.

I wouldn't go anywhere near Mobil rear gear lubes.

- Ken

 

[drtyler]

well the only issue was that 2 dealers told him it is currently unobtainable at the moment.

If the packaging says the oil is yellow metal safe, trying the 75W-90 may be ok. HPL and Amsoil say their GL-5 gear oils are yellow metal safe, but both are mail order. I don’t know about Valvoline or Mobil 1. It may be worth a call or email to them to find out.

 

[ckarpson]

 

[ckarpson]

yeah it doesnt make sense being a GL4 esp cause hypoid gears are gl5 ?