Join Date: May 2006
Location: Gaithersburg, MD
Car Year: 2009
Car Model: Outback XT-B
Feedback Score: 6 reviews
I think I was mistaken. MT-10 is a GL-4 spec. I must have been thinking about that.
You seem to be pretty motivated to try different gear oils. How many miles does your car have now? Some of the pros/cons you might be attributing to gear oils might, in fact, simply be from synchro "break in". During the first several thousand miles the manufacturing flaws and machining/casting debris is worn off through contact. Improved shift quality comes from that alone, even on factory fill oil.
Have you tried the Motul/Shockproof combo? I urge you to give it a shot. I think you, like everyone else who has tried it, will appreciate the shift quality. I can only think of one person who was dissatisfied with the results they had with that mix... and it turned out to be a broken synchro that was causing his issues.
09 SWP Outback 2.5XT 5MT 263whp, 337 lb-ft