I know that it is the exhaust gas temp . I have come to understand that EGTs are the highest when you are at low throttle when the engine is really working itself like towing in a high gear. So my ? is when you are running higher rpms in a lower gear to say the EGTs are lower because of higher rpms? and its combusting most of the fuel? Am I right ??

 

Its due to the higher airflow and lower combustion pressure. At higher RPMs the engine isn't working as hard to do the same work as you have more power strokes per second.