Transmission fluids used in NB Miata?

Just sold my 92 NA and bought a 99 NB. I used Redline fluids in the transmission and differential (non Torsen) with no problems. The NB did not want to coast well in gear so I sorted through the records w/car and found the fluid in transmission and differential (Torsen) had been replaced w/80W140 at a dealership. I checked the manual and found the factory recommends 75-90 in the transmission and GL5 in the differential. Went to Miata.net and read the oil and fluids forum. Found owners talking about Ford Fluid XT-M5-QS full synthetic MTL in transmission improved shifting in the NA Miatas. Nothing about NBs. What do you KNOW about using the Ford fluid in the NBs? Other suggested fluids? Thanks

The NA and NB transmissions are so similar as to make no difference. Use the same fluids.

I'm still using Redline MTL because it just plain works.

Same fluid choices apply to the NB

The Ford/Motorcraft XT-M5-QS stuff is the best fluid I've used for the Miata. Took a lot of the roughness out of my transmission, and even remedied my crunchy 2nd gear shift. However, the Ford stuff can be spendy. If not that, I would go Redline MTL/MT90.

Then I do Redline 75W90NS (non-slip) in the diff. Works awesome for daily/weekend track use.

Personal preference to a point.

I use Amsoil MTG in trans, SVG in diff. Redline for some reason made my MSM extremely notchy and rough feeling, so i swapped it out. Might have been fine in any of the 4 Miatas that followed, but staying consistent is easier for me to remember, and i already put MTG in everything else.

Desmond wrote: The Ford/Motorcraft XT-M5-QS stuff is the best fluid I've used for the Miata. Took a lot of the roughness out of my transmission, and even remedied my crunchy 2nd gear shift. However, the Ford stuff can be spendy. If not that, I would go Redline MTL/MT90. Then I do Redline 75W90NS (non-slip) in the diff. Works awesome for daily/weekend track use.

Agreed, used both in both 5 & 6 speed gearboxes. Redline's fine for the 5 speed, not as great in the 6 speed. I saw an improvement with the Ford stuff in the 6 speed.

I used MTL in my 2000. I did the shifter boots and turret oil too and it shifts like new.

Thanks, I used MTL in the transmission and synthetic in the differential and put some miles on it. Now it coasts and shifts great.

I found the same thing as Swank with my Mazdaspeed. MTL worked great in my NA, but for some reason made the Mazdaspeed notchy. It shifts much better with Motorcraft XT-M5-QS.

In reply to Keith Tanner:

Thanks Keith, used MTL as suggested and did a couple of road trips this summer. Transmission is shifting like new.