my M3 specs typically 10w40 for winter 20w50 for spring and summer. It is a 1995 E36 model, the 10w60 was for certain E46's.
The dealer will put the 5w30 BMW synthetic in my car, (they don't even carry a 40w), but it was eating oil (although not out of spec, I had not noticed this before - I was using 20w50 dino year round), the 20w50 would give me some lifter tap when cold, which went away when using BG MOA with the 20w50.
on bimmerfest, people are syaing go with the mobil 1 0w40, and are saying the 20w50 was just spec'd because of the resistance to shearing, in that synthetics were not widely used in 1994. but since the GC has had such glowing reviews and is close to a 40w and is being added after the ARX treatments, I figured I would give it a go.
The castrol site tells me to go with the 10w30, but isnt the GC better than that? Plus the GC has the BMW LL-01 rating.
Mobil 1 site recommends 0w40 b(which I understand shears down to 30w anyway)
Amsoil recommends 5w40 (I haven't seen to many reviews on this)
[ June 14, 2006, 07:11 PM: Message edited by: ssj4 ]