At first glance the icons for the German Heavy Tank and German King Tiger Tank look pretty similar and are a little hard to distinguish. When scouting the enemy, it is important to be able to determine their strength, which can be done easily by looking at the units themselves. The differences you will see are historically accurate, and easy to spot once you know what you are looking for. Pictured to the far left is the German Heavy Tank (Tiger I) and beside it is the German King Tiger (Tiger II)
 

The German Heavy Tank is incorrectly labeled in Axis and Allies RTS as Panzer VI Ausf. B which is actually a Tiger II, or King Tiger Tank. The more accurate labeling would be Panzer VI Ausf. E (original designation was PzKpfw VI Ausf. H and was redesignated as Panzer VI Ausf. E in 1943) or Tiger I.