NOTE: "Engines per move" in VehicleSize.txt does NOT refer to actual engines! It refers to movement points! This means that you do NOT have to settle for 1 engine per move and then a sudden doubling to 2 engines per move. You can assign more than one 'standard' movement to engines and then do some fancier math with the ships' engines per move (=movement points per move!) and actual max engines. I've assigned engines FIVE standard movement points in my mod. This allows setting Escort/Frigate to a max of five engines and still getting a movement rate of 6 ('engines per move'=4, max engines=5, 25/4=6 plus a remainder which is discarded). This allows a standard movement rate of one per engine with Destroyers and Light Cruisers ('engines per move'=5, max engines=6). And this allows a GRADUAL increase in engines needed to move larger ships. A cruiser can have 'engines per move'=8 and a max of 8 engines. So, it has a max normal movement of 5, rather than 6 and only needs TWO more engines for that movement. Then a battle cruiser can have 'engines per move'=10 and a max of 10 engines. It STILL moves 5 but needs more supplies to do it. Cool, huh? Then battleships and dreadnoughts have 'engines per move'=12 or even 15, and max engines=12 so they move either 5 or 4. I'm leaning towards the 4 but I'm still thinking about it. A base ship is a real hog. Diminishing returns should really kick in with a ship this huge, so I'm planning to have engines per move=25 and then a max of 15 engines. 15X5=75, 75/25=3 movement (plus bonuses, of course). I presume that the max movement points a ship could have would be 255, but I don't know. Someone will test it, I don't doubt.
Remember, this works with STANDARD engine movement. The bonus movement and the 'extra movment' of things like the Solar Sail and and new mods using this ability for different components will still be 1 for 1 in effect. The same goes for combat thrusters if you've gone and made them available for ships like I have.