Every thruster gets a small connection point in its center. Hover the middle of the thruster and connect a red or green wire to it.

Output: signal E = the thruster's current fuel efficiency.
- Vanilla thruster: 100 at low burn, dropping to about 51 at full burn.
- No signal when the thruster has no fuel.

Efficiency is calculated from how full the thruster's fuel and oxidizer buffers are (whichever is lower), using the thruster's own performance curve, so modded thrusters work too.

Settings (map settings)
- Update interval: how often the signal refreshes (default 10 ticks).
- Efficiency scale: 100 = percent, 1000 = per mille.

Notes
- A parked platform keeps full buffers, so it will read about 51 even though the thrusters aren't firing. The value is the efficiency the thruster would run at with its current fuel level.
- Works with blueprints; readers and their wires are restored when the thruster is built.
- Safe to add to existing saves; existing thrusters get readers automatically.
- Supports Factorio 2.0 and 2.1.