Originally Posted by sensi09
Per the manual:
Approved oils belong in the following viscosity classes: SAE 0W40, SAE 0W30, SAE 5W40, and SAE 5W-30.
Actually see no mention of the 10W60 weight in the manual.
You're looking in the manual for the general 3 Series cars. You need to be looking in the M3 Supplement, which DOES specify 10W-60 as the ONLY approved oil class, but under "Alternative oil types" says:
You can add small quantities of other synthetic oils. Only use oils with the following specifications:
Preferred: SAE 10W-60;
Alternative: SAE 10W-40, SAE 5W-50 or SAE 10W-50
API SJ/CF, API SK/CF or higher
So OP, it looks like none of those weights you found at Walmart would be good. I agree with others, just ask your SA for a bottle of OEM next time; many give you one for free, considering it part of Ultimate Service. And also for next time, before posting here,
. Just make sure you read the RIGHT manual.