Originally Posted by Surly73
Everything these days is a blend, and Group III/III+ is a heck of a lot better than it was a decade ago.
I believe that GC is a blend of III or III+, IV and V. There's definitely group V in GC because displays incompatibility with Auto-RX, which is composed entirely of esters.
I bet you really would have noticed your E46 being quieter with something other than M1 in there.
With my E46, I didn't notice a difference in noise between the BMW 5W30 and the M1, except at startup, the M1 was better, as expected. And the M1 definitely idles smoother in the middle of summer here in Phoenix.
The Europeans are strict on their labeling of oil, and according to this, it has no Group III. You're saying it does have Group III, can you point me to the information source for this? I was misinformed on the M1, I don't want to do that twice.