Is the Challenger's oil change notification based on...

1) ...a system that actually monitors the condition of the oil?

Or

2) ...is it just a "complicated" computer program that records miles driven, time running and possibly some other factors (driving style, etc)?

The owners manual only states it is determined by a "duty cycle", which I am thinking means #2 above.

Just asking because I guess I originally was under the impression it was #1 above. I did my first oil change prior to any dash indicator at about 2800 miles but I did not do any of the steps to reset the oil change notification system (page 172/173 in the owners manual). Now at 5600 miles, the oil change notification popped up. So now I am thinking I still have some time before I really need to change the oil, though I'll probably do it in the next 200 miles or so anyway.

Any other thoughts?