difference between Redline MTL and MT90?

[Neil]

I really want to change the oil in my S13's transmission (because i KNOW im using organic GL-3-4 and 5 rated cheapo oil). Ive already got 4q's of MTL here, and the only difference I can see is the MTL is 70w-80 and MT90 is 75w-90. Theyre both API GL-4.

The FSM 'reccomends' 75-90 apparantly because of the ambient operating temperature range. There's a little diagram in the fsm that essentially says 70w-80 is good to 86°f where the MT90 is rated up to 104°f.

So should I spend the $30 on MT-90 if the weather is going to hit above 90° a few times this summer? What's the worst thing that can happen if I put in MTL?

[sanioll]

the question is why use MTL, when the best choice for our daily hard driven workhorses is MT-90?? answer that, then you will see which one fits you best.

here's direct link to the manufacturer.http://www.redlineoil.com/prod...ID=18

and how to change the fluid, complete writeup:zerothread?id=95826

also, always search before creating any new threads, someone may have asked this question before.

[Neil]

Thanks but i did search. No one spoke about how using MTL would effect the car as opposed to MT90. I found a lot of 'my friend uses it and his car is still on the road, so it must be ok'

I also searched for BG Synchroshift but I cant find anything that specifically says it satisfies GL4 and the proper viscometric requirments. For $30 its worth the piece of mind alone to just go buy some MT90.