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      08-31-2020, 09:18 AM   #1

Drives: BMW i8
Join Date: Feb 2019
Location: Eldersburg, MD

iTrader: (0)

I changed the transmission fluid in my i8

I decided to change the transmission fluid in the Aisin transmission connected to the mid-engine, after seeing how many of the Mini Cooper owners have done this. Since some Mini platforms share a similar B38 engine and transmission design to the i8, their information was very helpful. Their fluid was coming out brown and so was mine, after 32k miles.

I could only drain 2.75L of the 5.5L capacity, due to there being much more fluid hiding in the torque converter, etc. I sent a sample to Blackstone for analysis, like the Mini owner did in the link below.

I'm considering doing this every 10k miles so newer fluid replaces older fluid, over time. The BMW ATF6 fluid that is recommended is cost prohibitive for doing this work. I did lots of research and the Febi Bilstein 29934 is a fraction of the cost and meets the same requirements for ATF6. Outside the US, some countries have access to the Aisin Premium ATF 6, which I couldn't get here in the US, or Aisin T-IV, but Febi was available at FCP Euro, so I'll do another drain and fill in the future and can send back the old fluid to FCP Euro for a 100% refund.

I daily drive my BMW i8 and enjoy doing my own service. If you're interested, please follow along on my journey to maintain and improve my i8.