So I'm changing the transmission oil on my 03 350z manual with 110,000 miles on the trans, I know I need API GL4 75W-85 but I cannot decide what brand to go with, I keep hearing all these different reviews on brands like redline, motul, royal purple, etc. I just want some other Z owners opinion on what I should go with? Thank you

 

Redline MT85 has the required viscocity Nissan specifies for our gearboxes, but I think the most important factor is it has enough friction designed in its chemical makeup to allow for proper synco operation. This synthetic lubricant is also engineered to withstand high heat and abuse, two factors our six-speeds are exposed to all too often.

 

So go with red line?

 

That's my choice. I use it in both my Z33 racecar and street car.

 

Cool, thank you!

 

go w/DK

 

+1 Yes.

 

Gonna go have to be that guy that recommends OEM fluid for the change. If Oem fluid was run for 110k, swapping fluid likely wont benefit anything. Some would say it may have the potential to do more harm than good (ie. dont change the diet of an old dog if you dont have to)

If you had a low mileage trans, then it would be a different story.

 

I'll be changing my fluid soon since I'm at 120k. Nissan recommends trans service @ 60k and 120k. I'm going to be using MOTUL that Z1 stocks when I change fluid.

 

Redline. IMHO much better than OEM. I put Redline in when I had OEM fluid with about 500 miles so I went from new to new and I loved Redline compared to OEM.