use Honda ATF (Automatic Transmission Fluid)
If you are worried about the transmission failing then sell the auto Prelude and buy a manual Prelude.
It will cost you probably around $3000 total after everything for the 5speed conversion.
I had GarageFive do a 5speed swap on my 97 Prelude a very long time ago.
If I remember correctly, I paid about 1300 for parts, some new and some used
And I think it was 1500 for labour at GarageFive? I can't remember of the top of my head, I'll have to find the invoice and double check but roughly 3K for the entire conversion.
Here is all of the information for the swap:
VancouverPreludeClub.net ? View topic - Automatic to manual transmission swap
I wouldn't do this again. I think its best to sell the car and purchase the same model, better model or different vehicle in manual.
Hope this helps
Cheers
Mike