Hi,
Is there a single point of reference for all lubricants for my 2.0 Sport NC? I am after, recommendations for LSD, Gearbox and Engine oil.
Thanks
See my selection below. Although you can’t see the spec of the diff oil (on the far right) make sure it’s GL4/5 spec. The middle gear box oil spec GL4 and engine oil 5w 30 fully synthetic.
Of course choose your brand, I’ve been using these oils for both of my NC’s and the gear/diff oils on my previous earlier models of MX-5 in various guises (name) the oil came in.
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I don’t know about a single point for this.
but I am about to have all my oils changed.
I know the engine wants a 5-30, I’m going to use a Castrol fully synthetic.
gearbox,
I’ve seen several American youtube videos where they all say to use the “unicorn tears” ford oil.
I’ve also seen a couple of UK youtube videos where they both recommended the same gearbox oil, sadly I can’t remember the name and I haven’t yet found those videos in my history.
edit: the American “unicorn tears” oil is Ford Motorcraft full synthetic
as to dif oil, I’ve no idea and seen no recommendations.
just found this rather helpful video
i do have 1 issue with this video he says to use a thicker oil.
i say: NEVER USE A THICKER OIL IN AN OLD ENGINE, yes it will quiet it down but it will also increase the stress on the seals of your old engine, and increased stress means a higher likelihood of a failure.
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Mick has nailed it above with good advice. Follow that and you’ll be fine 
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General oils for gear box 75w 90 to spec GL4. For diff again 75w 90 but spec GL4/5.
Castrol seem to change names on their products on a regular basis, just go with the specs on the can. The car handbook has these specs in the maintenance section along with a couple alternatives, I guess for different climates. Just follow those.
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As Mick.
BUT the diff on the 3.75 is GL5 only.
The transmission is GL4/5.
However, I have researched transmission oil to death and will now only use GL4.
Because NOT all GL4/5’s are suitable for “Transmission” due to the additives.
Which can ruin the soft metals within the gearbox.
GL5 also actually has much more EP additive which can bulk the gear selection.
My choice now is this for the 6 speed transmission.
If you are a Castrol person look at this.
This was the only other GL4 transmission oil available in the UK that I could find.
Red Line MT90 GL-4 Gear Oil.
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Thanks for all the extremely helpful responses. Should have said the car is a 2007 NC1 2.0 Sport.
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I’m going with Castrol for all my oils as it’s kind of a family tradition.
as for witch oils
il go with what mike has advised for the gearbox and Dif and a 5 30 full syn Castrol for the engine.
however, I also need to change my power steering fluid as I’m getting a little judder at low revs, zero speed when I quickly turn the wheel from lock to lock for parking.
can anyone suggest a good power steering fluid ?
Agreed, but as Mick said Castrol changes the names like the weather. I believe that the one I have just bought has taken over from the one Mick has. 
thanks mate
You are ok with GL4/5 on the 5 speed, if you have a 6 speed the recommended (service manual) says GL4.
That’s why I use the Syntrans on mine or whatever name they call it now.
We have Duretec (member) on here who supplies a special blend of oil for the gearbox, notably for the notchy change of the NC 6 speed box.
Yep, GL4 for my 6 speed transmission.
Of course Mazda may have indeed modified/changed the soft metal specifications of the NC2 gearbox.
Probably have different owners manuals. 
Sorry, but their is more chance of the Pope turning Protestant than me buying anything off him.
i also have 6 speed.
It would appear so, definitely mentions only GL4 in my manual for the gearbox, 6 speed. But says GL4 or 5 in yours
I have a 64 plate NC btw.
Weird eh.
Mines a 2013 3.75.
Manual is a June 2012 (Print 1).
But totally agree again will only use GL4.
Just checked, the 6 speed box changed (a few internal parts) for the NC2 but no mention of further changes to the NC3 (mine) gearbox wise.
So why change the gear oil spec between the two, anyone?
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Yes, that was my point and even more confusing as mine is an NC3 too.
The manual I have has the picture of the (3.75(NC3) on the front cover, so would assume not an old manual up to 2012, i.e. the 3.5 NC2.
I’am getting a headache now.
i have an nc2 6 speed, so i am very interested in what you guys decide is the correct oil for the gearbox.
i shall be watching this space with great interest.
right now it seems that is GL4 75-90 synthetic the correct oil for my gearbox yes?
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In my opinion yes and some others would agree.
However, some will disagree and use whatever and that is just human nature.
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