im going to get my transmission serviced tomorrow which fluid should i run Redline D4.... give me other good options please.. i dont know what the old owner was using by it sucks

 

Either ATF-Z1 (if you can still find it) or the new synthetic DW-1. Both OEM honda fluids.

 

I changed mine about a year ago and have put 13 thousand miles on the car. I feel like 3rd gear is not as smooth as it was especially when cold. Would the new synthetic be better for the tranny?

Small investment in lue of the consequences of needing a rebuild....

 

Yea, I have 20k miles on my last 3x3 ATF-Z1 change and its not as smooth anymore. I remember right when I changed it after about 20-25k and the difference was night and day. There is a small agreement on a popular oil forum that Z1 does not last very long and I tend to agree with that. Z1 is being phased out now and honda says that DW-1 is better.