What is "Propulsion Multiplier"?Speed = Base Speed × Speed Penalty × Unit Experience Bonus
Speed = Propulsion Max Speed × Unit Experience Bonus
(Whichever is lower.)
Base Speed = Engine Power After Upgrades × Propulsion Multiplier × Propulsion Terrain Multiplier / Total Weight
Speed Penalty is 3/4 if using a medium body on VTOL, 1/4 if using a heavy body on VTOL, and 1 in all other cases.
This speed is in units of world-coordinates per second. There are 128 world-coordinates in a tile, so, for instance, a unit with a speed of 128 would go at a speed of one tile per second.
That "Terrain Multiplier" is pretty important. You'd expect it to be 1× for all propulsions flat terrain, but it's actually 2.5× for VTOLs.
For example, count viper speed (weight 600, engine power 5750(whith upgrade) on tracks (+650% weight) witn heavy canon 10000 weight). In game speed 0.29 on road, and 0,24 on offroad.