[DexteRS]

I have a 2015 335i with the larger Brembo brakes, maybe it’s the m sport ones. I flushed my brake fluid before a track day, and used ATE 200 with the expectation it was better than oem fluid for the track.

Track day went well, although the brakes were definitely the weak point on the car. More importantly, my master cylinder squeaks, turns out because this fluid is too thin. When looking for others, there’s so many “LV” (low viscosity) options for our cars from rock auto, fcpeuro, etc.

What’s the reason for LV brake fluid, I’m trying to pick a non LV to put back in now to get rid of the squeak, but I wondered if people have recommendations for daily driving brake fluid with 1 track day per year in mind. Let me know what you guys think.

[SuperLomi]

There’s two that are commonly recommended for motorsport application.

Motul RBF 600 is one, and what I am using. Castrol SRF is the other.

Just realize these are more hygroscopic than many brake fluids you might typically use on a DD, and will need to be bled more often (at least once a season is recommended).

[AspektUSA]

Dot 4 LV is factory fill on basically any German car since 2010.

It works better with ESP systems and ABS.

Pentosin Dot 4 LV or ATE SL6 are what is put in at the factory.