So since I got the new Aluminum radiator and the Contour fans my car runs about 182 on my digital gauge.  70 degree days 182, 80 degree days 182, 90 degrees 182.  Pretty good this summer.  But I always drive during the day.  Tonight I stayed at a friends house a little later and turned the headlights on, on the way home not to see but to be seen.  Anyway I look down at the gauge 187.  Ok not to hot but higher than usual.  Get into my neighborhood and shut the lights off, immediately drops to 178