Nissan 370Z Forum - View Single Post - MT-90 from Redline

Ryan @ RJM · 11-03-2012, 04:19 PM

I've run multiple fluids through my 350Z/G35 and 370ZG37 transmissions for testing including 3 of the Redline MT oils both straight or in mixes.

Here are my observations.

1.) Redline MTL 75W90 straight
Felt good when cold, shifted smooth without notch under normal driving until you pushed it hard. Once the trans started getting hot it would get notchy quick and you could feel slight gear nibble at high RPM before it meshed the next gear. Down shifting was ok but no significant improvement over Nissan fluid.

2.) 50/50 mix MT90 and MTL
A little notchier then straight MTL in the morning for the first few blocks but warmed up quickly giving nice smooth shifts. When pushing hard or on really hot days it maintained its good shifting qualities with very minimal notch at high RPM. Downshifting was much improved once warmed up over MTL or Nissan fluid. Cold downshifting was somewhat worse then stock or MTL.

3.) MT85 Straight - No surprise here it performed pretty much exactly like #2 the 50/50 mix as that is all Redline has done to make its in-between formula.

4.) MT90 Straight-
Much notchier then straight MTL in the morning and takes longer to warm up. The colder it is overnight the worse it’ll be. Once warmed up it shifts like butter. When pushing hard or on really hot days it maintained good shifting no matter how hard you pushed. Downshifting was exceptional once warmed up over MTL or Nissan fluid. While cold the downshifting was much worse then MTL.

I wouldn’t us straight MT90 unless you live where the temperature remains fairly high year round so warmup isn’t as much of an issue or if you track the car regularly. Definitely not for cold weather use.

I’ve also tried the following mixes:
2 quart MTL + 1 quarts MT90 which is not as good as the 50/50 mix.
2 quarts MT90 + 1 quart MTL which is a better alternative for a mainly street driven car then straight MT90.

Now for the not so mainstream answer and for the best shifting fluid I’ve ever come up with for all weather and all purpose use... I mix 1 Quart Redline MT90, 1 Quart Redline MTL and 1 Quart of Amsoil Synthetic Synchromesh Fluid. This mix was tested in both my 06’G35 and my 09’ G37 and the results are like the best of both worlds. No notch when cold, no notch when hot or pushed hard, buttery smooth up shifts and really nice downshifts even if you’re lazy and aren’t rev matching. The synchro’s seem to love it as they quiet down and just all around seem to function faster especially when cold and on downshifts. Also zero grinds and upon draining at 5k miles there was no tell-tale synchro glitter or metal particles to indicate anything other then a healthy transmission.
Take with grain of salt and try at your own risk.

Also before someone asks me about our cars taking 3.2 quarts of fluid I’ve always used 3.0 quarts for changes as unless you leave if to drain for days you’ll never get that last 0.2 of a quart out and the 3.0 has always easily gotten me to the full mark when level… so no need to waste money buying a 4th bottle of fluid.

11-03-2012, 04:19 PM	#6 (permalink)
Ryan @ RJM Enthusiast Member Join Date: Aug 2012 Location: Ontario Canada Posts: 345 Drives: 09' G37S Coupe Rep Power: 13	I've run multiple fluids through my 350Z/G35 and 370ZG37 transmissions for testing including 3 of the Redline MT oils both straight or in mixes. Here are my observations. 1.) Redline MTL 75W90 straight Felt good when cold, shifted smooth without notch under normal driving until you pushed it hard. Once the trans started getting hot it would get notchy quick and you could feel slight gear nibble at high RPM before it meshed the next gear. Down shifting was ok but no significant improvement over Nissan fluid. 2.) 50/50 mix MT90 and MTL A little notchier then straight MTL in the morning for the first few blocks but warmed up quickly giving nice smooth shifts. When pushing hard or on really hot days it maintained its good shifting qualities with very minimal notch at high RPM. Downshifting was much improved once warmed up over MTL or Nissan fluid. Cold downshifting was somewhat worse then stock or MTL. 3.) MT85 Straight - No surprise here it performed pretty much exactly like #2 the 50/50 mix as that is all Redline has done to make its in-between formula. 4.) MT90 Straight- Much notchier then straight MTL in the morning and takes longer to warm up. The colder it is overnight the worse it’ll be. Once warmed up it shifts like butter. When pushing hard or on really hot days it maintained good shifting no matter how hard you pushed. Downshifting was exceptional once warmed up over MTL or Nissan fluid. While cold the downshifting was much worse then MTL. I wouldn’t us straight MT90 unless you live where the temperature remains fairly high year round so warmup isn’t as much of an issue or if you track the car regularly. Definitely not for cold weather use. I’ve also tried the following mixes: 2 quart MTL + 1 quarts MT90 which is not as good as the 50/50 mix. 2 quarts MT90 + 1 quart MTL which is a better alternative for a mainly street driven car then straight MT90. Now for the not so mainstream answer and for the best shifting fluid I’ve ever come up with for all weather and all purpose use... I mix 1 Quart Redline MT90, 1 Quart Redline MTL and 1 Quart of Amsoil Synthetic Synchromesh Fluid. This mix was tested in both my 06’G35 and my 09’ G37 and the results are like the best of both worlds. No notch when cold, no notch when hot or pushed hard, buttery smooth up shifts and really nice downshifts even if you’re lazy and aren’t rev matching. The synchro’s seem to love it as they quiet down and just all around seem to function faster especially when cold and on downshifts. Also zero grinds and upon draining at 5k miles there was no tell-tale synchro glitter or metal particles to indicate anything other then a healthy transmission. Take with grain of salt and try at your own risk. Also before someone asks me about our cars taking 3.2 quarts of fluid I’ve always used 3.0 quarts for changes as unless you leave if to drain for days you’ll never get that last 0.2 of a quart out and the 3.0 has always easily gotten me to the full mark when level… so no need to waste money buying a 4th bottle of fluid. __________________ Home of the A.F.P. Upgraded Clutch Pedal System. Smoother Launches, Smoother Shifts & Improved Clutch Control Like No Other Pedal Mod You've Experianced Before Guaranteed! Visit www.RJMPerformance.com or Email Ryan@RJMPerformance.com Also Don't Forget to Like us on Facebook www.facebook.com/RJM-Performance Last edited by Ryan @ RJM; 11-04-2012 at 12:05 PM.