[Rollo]

Okay, now I got it. The first 8 engines give you the desired speed of 40. (I was thinking the AI would add 40, because it does that in the unmodded game with base speed of 1). After that it will still add 37 engines, because of the misc. ability, regardless of how many engines are already on the ship.

If you use:
Misc Ability 7 Name := Standard Ship Movement
Misc Ability 7 Spaces Per One := 46,
it should add 32 (1500/46=32.6) engines on top of the first 8 giving you a total of 40 (that's how many you wanted, right?).

Rollo