One of the new features of 1.3 is Fake Thrusters.

What are these things, you say?

Basically, they're Thrusters (see St_equip.ini) with customized Effects (see Effects.ini) that don't do anything but look pretty.  And that's all they do.  Unlike "double Thrusters" which actually add more Max_Force (and give ships big boosts on speed), these Thrusters are in the Toolkit purely to provide some extra visual impact.

They come in two flavors:  reactive and passive.  Reactive Thrusters will animate when the Thrust key is pressed... Passive Thrusters just keep doing the same animation loop.  I have only used Playtrails and Fires (not Trails) because Trails will continually put a Trail out whether or not they're attached to an Engine (the trails are defined by the ALE, not by the Engine's INI).  You could, however, use Trails for extra variety.  But I doubt if it would add much to the game.

Here's the list.  I have gone through every Engine Fire and Playtrail hunting these down, so I am fairly assured that these are accurate at this point:

Fake_Thruster_Orange1 = Playtrail, Reactive.
Fake_Thruster_Orange2 = Fire, Reactive.
Fake_Thruster_Orange3 = Fire, Passive.
Fake_Thruster_Orange4 = Fire, Passive.

Fake_Thruster_Red1 = Playtrail, Reactive.
Fake_Thruster_Red2 = Fire, Reactive.
Fake_Thruster_Red3 = Fire, Reactive.
Fake_Thruster_Red4 = Fire, Reactive.

Fake_Thruster_White1 = Playtrail, Reactive.
Fake_Thruster_White2 = Fire, Reactive.

Fake_Thruster_Blue1 = Playtrail, Reactive.
Fake_Thruster_Blue2 = Fire, Reactive.
Fake_Thruster_Blue3 = Fire, Reactive.

Fake_Thruster_Green1 = Playtrail, Reactive.
Fake_Thruster_Green2 = Fire, Passive.
Fake_Thruster_Green3 = Fire, Passive.