Changing my gearbox fluid. Redline MTL or Redline MT-90 ?
 

Changing my gearbox fluid.
GL4

Redline MTL or Redline MT-90 ?


Spec is
Toyota MT Gear Oil Spce.II GL-3
75W-90

Redline MT-90 vs. MTL
• MTL is a low 75W, almost a 70W, at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise.
• MT-90 is a thicker 75W90 version of MTL. ... MT-90 is a 75W90 GL-4 and also satisfies motor oil viscosities SAE 10W/15W/40.


So, should I go with 70W85 or 75W90 ?
Easier cold shifting with the lighter MTL?

MT-90.

Tried and tested by many over here.

If the car is only a daily, MTL. If you track it, MT90.

Ive been running Pentosin MTF-2 (75w-80) for years now with no issues. So much better in cold weather. I think it might fall short when its REALLY hot out. Like 95F+ and I start driving harder.

Also, the new GR86 lowered the gear oil viscosity in the manual transmission. Couldnt tell you what, but I read it on the internet.

I just replaced my factory fill at 54k street miles and a few years track duty with MT90. Didn't see any reason to deviate from factory viscosities. Shifting is great so far, a bit better 1-2 vs. heavily used factory fill, see how it goes this Winter but not really worried...

Mt-90 is still pretty decent in the cold. I have been using it for quite a while.

MT-90 is preferred by many in Canada. I've only used it in like 8C (46F) during a fall track day. Not as notchy as stock/OEM fluid or Gear 300.