In what aspect does atmospheric pressure primarily affect engine performance?

Atmospheric pressure primarily influences engine performance through its effect on power and lift production. As altitude increases, atmospheric pressure decreases, which affects the density of the air. This reduced air density means that engine performance can be compromised because there is less oxygen available for combustion in the engine. Consequently, combustion engines generate less power, impacting their efficiency.

In aircraft, lift production is also affected by atmospheric pressure, as lift is generated based on the pressure differential created by the wings interacting with air. Lower pressure at higher altitudes results in a decrease in lift, necessitating adjustments to maintain performance. Therefore, understanding the relationship between atmospheric pressure and engine performance is crucial for pilots and engineers alike, as it directly influences how an aircraft behaves in flight.