2024 Subaru BRZ Manual Transmission Fluid Suggestions

[zeroptzero]

I recently brought home a 2024 Subaru BRZ, which will be a weekend only car that I will drive for 3 seasons only (Canada), and will be stored in winter. No track duty of any kind. The manual transmission spec is a 75w fluid, GL4. It will likely be a bit of time before I need to change the tranny or diff fluids on a low mileage vehicle, but I'd like to search for a decent fluid recommendation. My previous vehicle was a Honda S2000, and I had good luck running Amsoil MTF (5w30) in that tranny, but the specs were different than what my Subaru tranny has. 75w seems to be a pretty thin fluid spec , and quite different than 75w-90.

There is a Subaru Fluid 75w90 Extra S which is a GL5 that was used on the STi transmissions, but I always thought we needed to avoid GL5 fluids due to synchronizer concerns ?

Thanks for any recommendations and for taking the time to read this post.

 

[skyactiv]

The Amsoil 75W90 manual transmission GL4 gear lube has a really low pour point and appears to have PAO in it, so consider that.

 

[Rand]

There is no differential sharing the gear oil with the MT on the Brz.
so it can be thin and protect.
I would use the new redline low viscosity gl-4

MT-LV 70W/75W GL-4 Gear Oil​

owners manual says

 

[ceecbtg]

Any similar GL4 ZDDP options:
- RedLine MT-LV 70/75w
- Ford 75w FE D2 / Volvo 31280771 / Castrol BOT 303 PAO and 350 semi-PAO
- Toyota LV 75w
- Honda MTF-3 Ultra

 

[zeroptzero]

The Amsoil 75W90 manual transmission GL4 gear lube has a really low pour point and appears to have PAO in it, so consider that.

Thank you, I have access to Amsoil products and I have used them in the past, so that is worth knowing as a potential fluid, thank you.

 

[zeroptzero]

There is no differential sharing the gear oil with the MT on the Brz.
so it can be thin and protect.
I would use the new redline low viscosity gl-4

MT-LV 70W/75W GL-4 Gear Oil​

owners manual says
View attachment 263894

Thank you very much. I feel like I have been away from the oil / fluid world for a long time, LV and LX fluids are terms that I have not heard of in the past when owning other vehicles. It is interesting to see that LV is used for fuel economy benefits, using the other fluid may cause noise and performance symptoms as it is thicker ? Thankfully I have a while to think about this one but I do want to stock up on some fluids ahead of time. Thank you

 

[zeroptzero]

Any similar GL4 ZDDP options:
- RedLine MT-LV 70/75w
- Ford 75w FE D2 / Volvo 31280771 / Castrol BOT 303 PAO and 350 semi-PAO
- Toyota LV 75w
- Honda MTF-3 Ultra

Thank you for the additional fluid recommendations. Being a long time Honda owner and fan boy I don't recall seeing MTF-3 in Canada, the last version I seen was MTF-2, but I will check around. I remember using Amsoil MTF (5w30) tranny fluid on my Hondas with good results.

 

[zeroptzero]

I haven't been able to locate what Subaru dealers install that meets the Manual Transmission Gear Oil LV 75 t5what is listed in the owner manual. I will keep looking to see if there is a dedicated product. My other choices will be Redline MT-LV 75 which sounds like a nice option, and I have always been a fan and user of Amsoil MTL (5w30) which had worked well in cold temps despite slightly thicker than 75w LV specs. I am not sure if I should go with the LV 75 viscosity (around 6 cst ) of the Amsoil fluid viscosity (9 cst) , the Amsoil always worked well in my Honda S2000 tranny which seems to be similar to the BRZ 6mt

 

[zeroptzero]

I just finished the installation of Redline MT-LV into my BRZ 6MT. First test drive this afternoon. Everything feels real good. First thoughts on the transmission fluid is that it feels better than stock. The factory fluid seemed pretty thin when it drained, thinner than the Redline MT-LV, but the Redline meets the factory specs for viscosity. There was little metal on the drain magnet. So far the transmission seems to shift better into 2nd gear, and 6th gear, the two spots where the OEM fluid didn't feel great. The OEM fluid felt good and would have been fine, I think the Redline MT-LV is better though. It also feels better in 2nd gear double clutch downshift, something the OEM fluid didn't feel great at. Temps today are around 50 degrees, cool but not cold. I believe it usually takes about 2 weeks for the new fluid to mix with the old fluid and to plate up on the metal surfaces, and become more homogeneous compared to the initial drive. I will monitor it over some time, so far no issues. I know if it did not feel good on initial drive I would be draining it asap, but so far so good.

 

[Dave Hess]

You want a smoother shifting manual transmission ?

I ordered a 2025 BRZ and still waiting for it.

 

[kschachn]

@MolaKule might have input on this common question.

 

[zeroptzero]

You want a smoother shifting manual transmission ?

I ordered a 2025 BRZ and still waiting for it.

I mostly wanted a dedicated MTF fluid in the transmission, not just gear oil of the right viscosity. I always felt that a manual transmission should have a friction modified MTF, gear oil works good enough, but why not search for better ? I do this on all of my vehicles , it was the same thing with my Honda S2000, where I preferred to use the Amsoil MTF 5w30 fluid, I would have tried it on my BRZ but the viscosity of the Amsoil fluid is higher than the factory spec, Redline MT-LV is in line with factory viscosity specs.

The BRZ transmission shifts well enough in stock form, there were just a couple spots where it didn't feel perfect to me, keep in mind we are still in winter mode in my region.

 

[zeroptzero]

@MolaKule might have input on this common question.

I used his advice in choosing the Redline MT-LV , his list of MTF fluids is a great resource, along with comments he provides to posts like mine. A great resource.

 

[zeroptzero]

You want a smoother shifting manual transmission ?

I ordered a 2025 BRZ and still waiting for it.

Mine is a brand new 2024, I just brought it home from the dealer showroom about 3 weeks ago. Incentives on 2024's were decent and I could get the 2024 right away since it was in the showroom at my dealer. It was only a few days to bring it home after plunking down my deposit. I wanted to try out the 2025 since it has a sport mode button which the 2024 does not, sounds cool, but I took the 2024. They had some nice TS models on the lot with the big brake kit and alternate dampers, but none in blue lol I wanted the blue.

 

[MolaKule]

I recently brought home a 2024 Subaru BRZ, which will be a weekend only car that I will drive for 3 seasons only (Canada), and will be stored in winter. No track duty of any kind. The manual transmission spec is a 75w fluid, GL4. It will likely be a bit of time before I need to change the tranny or diff fluids on a low mileage vehicle, but I'd like to search for a decent fluid recommendation. My previous vehicle was a Honda S2000, and I had good luck running Amsoil MTF (5w30) in that tranny, but the specs were different than what my Subaru tranny has. 75w seems to be a pretty thin fluid spec , and quite different than 75w-90.

There is a Subaru Fluid 75w90 Extra S which is a GL5 that was used on the STi transmissions, but I always thought we needed to avoid GL5 fluids due to synchronizer concerns ?

Thanks for any recommendations and for taking the time to read this post.

I thought we answered your questions here:

Z

Thread 'Would My 2024 Subaru BRZ Transmission 6MT Be Considered a Synchromesh Transmission'

Mar 2, 2025

For my 2024 Subaru BRZ with the 6MT transmission, I've been considering the Amsoil 5w30 MTL as I always had good luck with it in my Honda S2000, even in very cold winter temps. Amsoil says that it is made for Synchromesh Transmissions. I want to use an MTF rather than gear oil that some people use. I am just wondering if my transmission is considered a Synchromesh transmission ?

I've heard people say the BRZ transmission is very similar to the S2000 tranny of the past and Amsoil worked well for me in that car. Subaru suggests a 75 W fluid and 75W LV as options. I don't...

• zeroptzero
• Replies: 13
• Forum: ATF, Differential, Trans, Brakes, P/S

• 

 

[zeroptzero]

I thought we answered your questions here:

Z

Thread 'Would My 2024 Subaru BRZ Transmission 6MT Be Considered a Synchromesh Transmission'

Mar 2, 2025

For my 2024 Subaru BRZ with the 6MT transmission, I've been considering the Amsoil 5w30 MTL as I always had good luck with it in my Honda S2000, even in very cold winter temps. Amsoil says that it is made for Synchromesh Transmissions. I want to use an MTF rather than gear oil that some people use. I am just wondering if my transmission is considered a Synchromesh transmission ?

I've heard people say the BRZ transmission is very similar to the S2000 tranny of the past and Amsoil worked well for me in that car. Subaru suggests a 75 W fluid and 75W LV as options. I don't...

• zeroptzero
• Replies: 13
• Forum: ATF, Differential, Trans, Brakes, P/S

• 

Yes you did, and you did it well, andy our replies were appreciated. I wasn't asking any further question here. In this thread David Hess asked if I was looking for a smoother shifting transmission, but that was not my motivation, I was wanting to change the tranny fluid in order to get an MTF in use rather than just a gear oil. I have no further questions and my decision was made and I have a new fluid in use.