Transmission fluid blending Redline MTL and Motul Gear 300 okay?
 

Hi,
I bought 2 QT Motul Gear 300 for the diff... I am going to buy some REDLINE MTL for the tranny... any issues of blending the two manufacturers gear oil? I will get 2 QT of REDLINE MTL so any negative drawbacks of mixing / blending gear oils? I am going to mix a little bit of the MOTUL Gear 300 into the tranny with the Redline MTL. Please let me know. Thanks,

Gear oil blending has become popular on sites like nasioc because the easiest shifting oils are GL4's but most Subaru's (with the exception of the BRZ) spec GL5 since the transmission/diff combination needs the higher anti-wear additive level, but does not like too high of a level of friction modifiers.

Not sure about the BRZ, but my owner's manual specifically says not to blend gear oils and I have never blended a gear oil in 16 years of using synthetic gear oil in Subaru tranmissions.

From the good reviews that I've read here on Red Line MTL and 300V, there probably isn't a need to mix them. As far as any negative drawbacks, I would probably ask someone that is more qualified to answer the question (like someone that blends gear oils for a living :)).
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=postlist&Board=16&page=1

Who knows; maybe you can try it and create "imom cocktail". :)

-Dennis

It was just a matter of convenience... I bought 2 QT of MOTUL Gear 300... 1.2 Liter goes to the differential...then I really wanted 2 QT for the tranny with REDLINE MTL since folks say it helps with the 2nd gear shifting...so I need 2.2 Liters I believe...so I thought I top it off with Motul since I see people running them already in the tranny... but I didn't know if there are any drawbacks of mixing gear oil.

i'm not oil expert. According to redline website, they say that the MTL is compatible with petroleums and other synthetics. MTL is GL-4, Motul gear 300 is GL-4/GL-5. If I were you, I would top off the rest 0.2L with motul..