So when it came time to change the fluid in my tranny and diff. I knew I wanted to go synthetic and I didn't know which brand. If you do searches on this forum you will find info on the other brands Redline etc... But hardly anyone talks about NEO. I saw on Mazdatrix website they recommended it and thought I would give it a try. Well needed less to say it works great. I use to have a weird grinding / whining noise when cruising in 4th gear. After switching to this fluid that noise is gone. And shifting between gears is 10x smoother. If anyone else has anything else to say about NEO post it here.

FYI I used 75-90 HD.
http://hankthomasperformance.com/ sells a gallon for $39.99.