I have a 2011 WRX with 18k on it. For the first 12-15k miles the temp gauge was always dead in the middle under normal driving conditions (street and highway). Now for the past 3-5k miles it is consistently sitting just above the middle mark under the same driving conditions. The needle will settle back to the middle position when idling at a stop light.
The coolant level is about 3/4 of the way to max.
I'm not too concerned but I'd like to know if my car is slowly losing coolant or what might cause the temp to rise under the same driving conditions.
My car is stock except for some bushings and swaybars.