after an oil change what should the onboard computer ideally read as oil level in the OM648?

I have been searching and I find mainly oil spec info but not capacity. The manual says 8qts, but my level reads 7.9qts and I get a excess oil warning. What little information I have have seen say anything from 6.5 to 7.3 Liters (6.8-7.7US qts).

Also should the oil only be checked when warm and letting the car sit 5-10 min or can it be checked at dead cold after sitting overnight.

Note: when using the oil check method in the manual it simply says "oil level ok".

I appreciate any help. I don't want to drive the car again until I know the level is in the correct range.