Antimatter inducer

From Memory Alpha, the free Star Trek reference.

Antimatter inducers are warp drive components associated with a starships consumption of fuel. The principal behind the component is that the more efficient the inducer is, the less fuel is consumed during warp flight. (ENT: "Twilight")

In an alternate timeline, Jonathan Archer came up with a way to upgrade the antimatter inducers. Upgrades based on his specs were described as "working nicely." (ENT: "Twilight")

Montgomery Scott initially had difficulty locating the "damned" antimatter inducer on the Klingon Bird-of-Prey they managed to hijack from Commander Kruge. With Pavel Chekov's assistance, Scott pressed the necessary button to activate the inducer which quickly brought the ship up to full power. (Star Trek III: The Search for Spock)