Checking the oil is the simplest of tasks: The tendency to over analyze is epidemic here: Shut off the engine with the car on a reasonably level spot, raise the hood, wait two minutes (with a warm engine), pull the dip stick, wipe it down, put it back, wait 5/10 seconds, pull it out again and read it.
If the level is between the marks, put it back and drive on. If the level is at the minimum mark add 1 quart and recheck as above. Add oil only when the level is at the minimum mark. Thats all. Synthetic or dino no difference.

__________________
N. Hodges
1994 S350
1987 300 SDL (for sale)