I tried 5 different oils in my '02 AP1 (OEM Honda MTF I, Redline MTL, Redline MT90, GM Synchromesh, and GM Synchromesh Friction Modified), and the only one that did well was GM Synchromesh Friction Modified. Redline MTL was noce ONLY when cold, and was way too thin when it got hot. It would start grinding very badly if I drove agressively on a hot day. That's why I tried MT90, but it was too thick when cold. I considered a 50/50 mix, but never tried it. I had such good results with GMSFM that I never tired anything else.

 

BTW, I tried GMSFM in my '08 AP2, and it didn't seem any better than OEM Honda MTF II.

 

I hear people doing that gernby:

the 1 quart MTL and fill the rest with MT-90.

 

I use RL MT-90 in the tranny,and Amsoil 75W140 in the diff...

 

I tried the Honda MTF as well, still hard to shift and that shouldn´t be a problem on a low milage car like mine.
Will try a few different oils and get back, we use Castrol 75w90 in the race cars and they are also used during hot days to 90%.

 

Hope this is true