Elf NFP in mine. I have tried the Redline MTL in the past, and although I couldn't fault it, I also couldn't tell any improvement/difference from OEM/Elf.
there is a post by @TB Rich somewhere on the forum, why NFP is supposed to be the better option (over NFJ). had a search, but can't find it. can't remember if it was in his project thread or if it was a specific 'gearbox oil' thread.
I used 500ml of Castrol Syntrans and the rest Honda MTF
The Honda stuff as I’ve always found it to improve day to day gearchance, especially when cold.
A bit of syntrans so there’s some synthetic oil in there for track use that will hold up better at the likely extreme temps.
Worth also mentioning I like to change gearbox oil each time I do engine oil, the poor stuff has to put up with horrendous temps, especially if used on track.
Lovely typically Japanese vid here with the owner of Spoon Sports explaining the importance of gear oil changes:
There is is really big difference compared to original and ELF NFP.. when it is cold weather.
My previous gordini was really difficult to change gears when temp was -2 or something. With NFP it is smooth and easy.