Plain English Meaning
A gauge that shows how hard the engine is working by measuring the pressure of the air being drawn into it. Higher pressure means more power.
Full Definition
A cockpit instrument that measures the absolute pressure of the fuel-air mixture inside the engine's intake manifold, displayed in inches of mercury (in. Hg). It indicates the power being produced by a piston engine, and is the primary power-setting reference for engines equipped with a constant-speed propeller or a turbocharger.
Context Anchor
Seen on the engine instrument panel, especially in airplanes where sets power by watching engine and .