CPL,
The con is definitely the cost. At $8 a quart, RedLine MTL costs about twice as much as Honda MTF and about four times as much as regular old 10w30. Additionally, RedLine does not recommend extended drains in the tranny as there is no filtering mechanism. So you pay more and don't get the extended drain benefit like using synthetic motor oil. Those are the only cons I can think of.
The pros are the same as any synthetic based product. This stuff just doesn't break down as quickly as an organic oil.
Considering RedLine's reputation, I don't think you can go wrong with the product. I've certainly been happy with it.
Bogatyr

 

like Bogartyr said, the synthetic is too slippery, and the synchros will burn up. As for dyno juice ruining a clutch? That's is so damn funny I almost wet myself. If the internals of a tranny have anything to do with a mating surface outside the transmission, then you have problems. I always run 10w40 in the summer, and 5w30 in the winter. Anything more than 30 and the tranny shifts hard in the cold. I swap trannies around like there's no tomorrow, and I've NEVER had a problem using Valvoline. I swear by it. Penzoil and other high parafin oils can gunk things up. So stay away from them. Other than that, any dyno juice should be good to go!

 

i picked up a 4 litre of SJ grade, i found it at... London Drugs of all places. they were getting rid of old stock i guess.

 

I bought the Redline stuff. Yes it's expensive but you dont change it as often as engine oil.

 

8$ a quart is not that expensive. You arent going to change it that often, but it does help. The honda MTF is good too. Using an engine oil in a tranny is a definite no-no ive always been told. But I thought the honda MTF is part-synthetic? or is it?>

 

are you guys sure you should be running 10W30 and such in your tranys? I work for an oil company and we use everything from 75W90 to 85W140 for trannys.. if you look at any "Manual transmision oil" its going to be around 80W90 and such.. like that redline stuff is 75-90 i beleve.. just the idea of running an motor oil where a gear oil should be run makes me wonder..

but i could totally be wrong.. most of the tranny oil we sell is to rigs and larger trucks..

 

I PERSONALLY use 10w-30 and so do people I know. I run my car hard as hell and I've never had transmission problems. Heck, even the manuals tell you that you can use 10w-30.