Choices of diff oil for the Miata 2002

[Pesca]

Hi,

I went to WM and CT last sunday to find rear diff oil for the Miata, which probably never have been changed its entire life.

I need to change the manual transmission oil so I want to tak ethe opportunity to do the rear diff too. I have the Ford oil already for the trans.

Here in Canada (maybe I don't go to the right stores too), we don't have a lot of choices:
At WM, they only have their Super Tech gear oil (about 7$ for a quart).
At CT, they have their own brand, Motomaster, either in conventional (about 7$ a quart) or synthetic (about 14$ a quart). they also have Royal Purple and QuakerState (at between 14 and 22$ a quart).

Could not find any Mobil 1 LS 75w90, Motul Gear 300 75w90, or Redline 75w90, which have been recommended on the net.

So I have two questions, as I don't plan to do it often, so I want to do it right the first time:

- Is Motomaster synth a good gear oil to use? As good to Mobil 1 or Redline?
- If not, where can I get Mobil 1 or Motul Gear 300 gear oil?

Thanks for your help,

 

[SwampSurvivor]

What's wrong with the Supertech gear oil?

 

[GutsyGecko]

Use the royal purple.

 

[NMBurb02]

The specs for the Renewable Lubricants gear oil I just put into the Burb are pretty impressive and can be bought on Amazon for a pretty reasonable price. It is $16/qt or $48/jug (4 qt).

(Thanks dparm for the recommendation.)

 

[redbone3]

The synchro's will be happier with Redline MT. The differential oil from Walmart should be fine.

 

[aquariuscsm]

Amsoil MTG for the transmission and Amsoil SVG (if yours takes a 75W) for the diff. If it takes an 80W,go with Amsoil AGL.

 

[Pesca]

Hi,

To answer some questions:

- Nothing wrong with SuperTech, that is why I am asking your opinion on it. My only problem is it is not synthetic, and I would prefer go that way as I don't plan to change the oil often.

- Any hint/reason on why use RP more than the other, except the fact that it is the most expensive of the lot?

- How much is the renewable lubricants gear oil? I will check on Amazon as not all products on .com site can be shipped to Canada.

- I cannot find Redline locally even if it got good review on internet... and I believe, like me, you don't any way to find a store who got it near Montreal. For the tranny, the ford oil is the best for the miata, it has be proved several time in the past, that is why I bought it.

- I thought about AMSOIL but it may end up quite expensive at the end of the day.

Does anyone have an opinion on the motomaster gear oil as it is the most common around here? From what I understand, Motomaster engine oil is made by Shell for CT. Is it the same for the gear oils?
Do you know if I could have more choice, and maybe find the Mobil 1 or Redline, going to a NAPA store? Any other store I can find around Montreal that sell gear oils?

Thanks for all your help so far.