when topping off eng oil,do you top off while running ?

leave running. just remember that cap is HOT. Use a rag to hold it..

 

I'm sorry to repeat what has been said elsewhere, but I'll add this anyway- make sure you have the oil fully warmed up and the car is level- it's amazing how much the oil expands vs. checking with a cold or coldish temperature...you do not want to over fill- I would aim to get the level somewhere between the max and min line or 2/3s up from min to allow some expansion room. It's a pain in the butt because the oil lid is so hot and your reaching over an even hotter muffler, but it's a bigger pain in the butt to use a turkey baster as a siphon to pull out hot oil that was overfilled (my car was a little more than a quart overfilled when I got it and that's what I had to do)- you don't want to overfill because it can lead to bigger problems like messing up the intake or maybe even getting up to the mass airflow sensors (I had to replace a MAF and I wonder if it was due to an overfill prior to my ownership or the overfill when I took ownership).

I'm always very careful as I remember a guy on here (forget if he had a 355 or 360) talking about how he had a nice burn mark on his leg in the shape of two muffler outlets from his tubi!

Oh to your original question, yes you can add with the car running- probably easier that way in fact.

 

How much is oil will take a min reading up to the maximum?