Installed new radiator and thermostat both from Autozone over the weekend, also flushed system and filled with distilled water and 3.5 gallons of Zerex. Now temps are slightly higher when running highway speeds both day and night. before temp was just below or on 200 now it is on 200 or just over. Doesn't seem like a big deal just wondering why it runs hotter now.

 

You may have air in your system.