Manual Trans Fluid - Redline ATF D6 vs MTL vs OEM
I'm looking to change out the transmission fluid on my 6-spd E90 328i. I've seen 3 main suggestions: Redline ATF D6 (not D4, I live in Iowa, it gets cold), Redline MTL and OEM Bmw MTF.
I've heard people saying they prefer both the Redline products over OEM, but there doesn't seem to be much of a consensus. I've read NOT to use Royal Purple since the OEM fluid left in the tranny/diff will degrade it after a few months.
ECS tuning recommends the Redline MTL and I'm somewhat inclined to listen to them since I assume they know what they're doing (they've been in business for quite a while).
I'm also planning on using Redline 75w90 for my diff. It matches the spec for the OEM non-LSD fluid from what I've seen.
Anyone want to chime in on what to use?