shall we talk about transmission AND diff oil....

[handballallday]

i know this has been discussed all over this forum as well as Pelican and bimmerforums.com but THIS is for my own purposes of knowing because this is such a widely discussed and a little confusing topic.

I've changed the tranny and diff oil on both my 91 Miata and 96 RAV4 with just regular conventional Valvoline manual transmission/gear oil from Autozone and both have been running fine for 2 yrs now.

i have a manual 97 318ti with 122k miles which i daily now instead of my manual 96 2dr RAV4. I know the owners manual says to use "ATF" for the tranny and "Brand name hypoid gear oil" for the diff. So my here are my following question....

- why ATF and not MTF? I found that rather weird and opposite.
- when they say "Brand name hypoid gear oil" do they mean Valvoline, Castrol, Lucas, Mobil, Red Line, and/or Swepco?!
- i noticed Pelican sells both Red Line D4 ATF and Swepco 201 but Pelican recommends Swepco 201. What's the difference between the two? Red Line is synthetic and Swepco is more thicker oil? Can i just go with a conventional ATF or even a high mileage ATF for the tranny?
- same goes for diff oil.... i see a lot of people recommending Red Line 75W90. Can i just go with a conventional brand name 75W90?


mind you.... i don't race/track any of my cars and don't plan on to. Don't much care for it. Just daily driving and occasional spirited driving. Nothing crazy. I don't need high performance expensive brand name oil. Just oil for daily use BUT if the Red Line and/or Swepco stuff is worth it then i guess why not? So with that said what are your suggestions, recommendations, advice, and experiences?

I'm honestly just thinking of going with conventional or even high mileage tranny/diff oil rather than spending more for the Red Line stuff. Call me conservative or frugal but not cheap.


EDIT: the last post in this thread talks about Jim Blanton using Red Line D4 ATF for the tranny and Red Line 75W90 for the diff in ALL YEARS of BMW. Who is Jim Blanton? Seems like a well known mechanically inclined guy in the BMW world. Any feedback on this? THIS is making me lean towards Red Line.

http://forum.roadfly.com/threads/944...al-fluid-specs