IMO there are 40 different tracks because sections do count. YOu can't say (for example), that mandrashee 2 and mandrashee 3 are that identic that you can call them one track.

Btw: there're alot (little) things more I like in Fusion that I notice when I actually play the game. Like the different colored trails and or the huge number of stripes on the tracks that are passing by very fast and thereby give you a better speedfeeling. I also like that some ships have more than just one exhaust engine.