for the longest time they were running conventional in my vehical, till i switched to syntetic (royal purple), at first there was a huge change in performance that i could feel, but over time the cost of RP, was outa line so i went to mobil one 5w-30 (bad idea???) and on the other note i put royal purples geat oil 75w-90 in my tranny bit it seems that the trannys been alot rougher since the change any idea's?

 

Redline MT-90 seems to be what most people run in their trannies. I just put some in mine today, really helped smooth out the shifts.

I've been using Mobil 1 5w-30 full synthetic for the past 20k miles in my motor too. Runs great.