In Reply to: Re: And which one is the best ##W-## for M3s?? (eo posted by Pete on January 09, 2000 at 08:52:32:
The "W" stands for "Winter" usage which generally indicates a multi-viscosity oil. That is precisely why you see two number such as 10W30 which is the oil's resistance to flow (called "viscosity") at different temps. "W" does NOT stand for weight!
Check out: http://www.audicoupe.demon.co.uk/engineoil_bible.html
This is a pretty informative site and should answer most of your questions. ;-)
: : Depends mostly on location. 15w-40, 10w-40, some people use 5w-40 and under road racing conditions, it's 20w-50 or straight 40 or 50 oil.
: when you straight 40 or 50, do you mean 40w or 50w? if so, isn't that a bit thick for an engine and is more suited as gear oil?