Oil Change at dealership

polarity

Hey guys just a quick question if anyone has run into this. When I purchased my Z in Feb I got some type of maintenance deal with it. For 45k miles they take care of all my service for free. Everything has been going great taking it to them, when I get my slip back at the end it always says they put in the 09 370z/altima ester oil.

This time I did not get the same slip as usual because I brought it in late Saturday, they just gave me kind of a checklist of everything they did. Anyway on to the question, the car oil temp has been sticking around 220 majority of the time when driving around here in the Mississippi heat. Yesterday I took it home and the temp never went above around 180. I even hit the interstate and took the long way home an extra 8 or so miles out of the way (prolly 25 miles in total). Any idea why the sudden drop in oil temps?

-William