WIKI entry
http://www.arcengames.com/mediawiki/index.php?title=AI_War_-_AI_TechsAt What AI Progress Does The AI Tech Level Increase?
A: The AI will go up a tech level on the following AI Progress schedule:
Mark II: 300 - ( 10 x Difficulty of AI Player )
Mark III: 800 - ( 10 x Difficulty of AI Player )
Mark IV: 1200 - ( 10 x Difficulty of AI Player )
For "Technologist" type AIs, if their level would be II or higher, they are instead Mark IV. If they would be below Mark II, they will instead be Mark III.
Additionally, when playing on difficulties greater than 8, the AI players will always be one Mark level higher than normal, until they hit Mark IV.
So, for example, when playing against a level 5 AI the AI would tech up as follows:
Mark II at AI Progress 250 (300 - 50)
Mark III at AI Progress 750 (800 - 50)
Mark IV at AI Progress 1150 (1200 - 50)