M42 Fluids

[Nick_S]

I have been searching and can't seem to find very good answers for what fluids to run in my car, 91 318is. I don't have the manual for the car so I can't look in there and searches online seem to be kind of all over as far as what people run. So, basically I'm looking to change all the fluids in the car since I just bought it. And just wondering what is OE and/or what you guys would recommend for the basics:

Engine oil:
Trans:
Rear dif:


Also.. spark plug gap:

I have a 3 quarts of Mobile1 75w-90 laying around and had seen a few people use that in the dif and even in the transmission...but also saw people using ATF for the trans I believe 90w-140 for the dif?

I found this thread but it's pretty difficult to make out what goes with what.

http://www.m42club.com/forums/showthread.php?t=71

Sorry for the noob-ish questions but hopefully you can help.
Thanks
Nick

[Matt-B]

in the summer, i used 10w40 in my m42, winter 5w30

trans, ( 80 90 trans fluid ) cant remember it was red

Diff 75w90 LSD additive ( mobile 1 diff fluid for LSD cars )

[Ryann]

Engine oil- Redline 15w 50 year round
Trans- Redline MTL 70w80 GL-4
Diff- Redline 75w90 GL-5