I own a 2023 BRZ and been meaning to change manual transmission fluid.
On one hand, the transmission is mostly same from previous generation which recommended 75W90, but this generations manual recommends 75W.
And on other hand, Toyota's manual says lower viscosity oil was adopted (adding screenshot), I am not sure if that means mechanical changes were done that somehow would have negative effect on thicker oil, making thinner oil preferable.
The transmission is TL70 based on AZ6.
I gathered viscosity number of fluids people used in previous gen and feedback people had about them. Just for simplicity purpose I am adding options from redline. Few members used options from Pentosin or AMSOIL which in viscosity was similar to one of these options and that didn't get me much further.
I also heard argument that lower viscosity is due to EPA only and would cause more wear.
Other data I could find was extreme temperatures someone saw on track (as high as 147°C).
Which oil should one pick? Based on previous gen's recommendation? Current gen's manual? Somewhere in between? Should it depend on use? Temperature range?
I am in PNW and I track car 6-8 times a year. I am not aggressive driver. But I would still be interested in why would one choose higher or lower viscosity. I put 3-5k miles on car a year and I am planning to change MTF every year.
On one hand, the transmission is mostly same from previous generation which recommended 75W90, but this generations manual recommends 75W.
And on other hand, Toyota's manual says lower viscosity oil was adopted (adding screenshot), I am not sure if that means mechanical changes were done that somehow would have negative effect on thicker oil, making thinner oil preferable.
The transmission is TL70 based on AZ6.
I gathered viscosity number of fluids people used in previous gen and feedback people had about them. Just for simplicity purpose I am adding options from redline. Few members used options from Pentosin or AMSOIL which in viscosity was similar to one of these options and that didn't get me much further.
I also heard argument that lower viscosity is due to EPA only and would cause more wear.
Other data I could find was extreme temperatures someone saw on track (as high as 147°C).
Vis @ 40°C, CSt | Vis @ 100°C, CSt | |
Toyota LV 75W MT | 30 | 5.7 |
Redline MT-LV 70W/75W | 29.8 | 6.5 |
Redline MTL 75W80 | 50.8 | 10.4 |
Redline MT-85 75W85 | 62 | 12 |
Redline MT-90 75W90 | 82 | 15.5 |
Which oil should one pick? Based on previous gen's recommendation? Current gen's manual? Somewhere in between? Should it depend on use? Temperature range?
I am in PNW and I track car 6-8 times a year. I am not aggressive driver. But I would still be interested in why would one choose higher or lower viscosity. I put 3-5k miles on car a year and I am planning to change MTF every year.