What does manifold pressure measure in an engine?

Manifold pressure measures the pressure inside the induction system of an engine. This pressure is an important indicator of the engine's performance and is typically measured in inches of mercury (inHg) or kilopascals (kPa). It reflects the amount of air (and fuel) that is being drawn into the engine's cylinders for combustion.

Understanding manifold pressure is crucial for pilots, especially when managing power settings during different phases of flight. A higher manifold pressure generally indicates an increase in engine power output, while lower pressure can signify reduced power and efficiency, especially during climb or cruise phases. This measurement helps pilots make informed decisions regarding engine settings and performance, ensuring safe and efficient flight operations.

Other options, while related to engine systems, do not pertain directly to manifold pressure. For instance, the fuel system's pressure, oil system pressure, and cabin pressure all relate to different functions within the aircraft and are not indicators of engine induction efficiency. Therefore, the focus on the induction system is key to understanding overall engine performance.