btbiii
03-15-2009, 08:14 AM
I just purchased an 1988 M3 Thursday. The previous owner has been running 5W-30 & 10W-30 Oil in vehicle. I have always run 15W-50 in my previous E30's per the original owners manuals. I have a Chiltons manual that also calls out 15W-45/50 weight oil. Which is correct? Thanks in advance for any help.
