The Thruster Fuel is used in Thrusters. It's used to power them so they can give a boost to the ship's speed. It is more efficient than explosives so it is highly recommended to make instead.
The first thruster fuel that is added to the thruster gives 1/64 fuel power and then the second one gives 3/64 fuel power.
Example
1/64 First fuel added
3/64 Second fuel added
5/64 Third fuel