What effect does applying carburetor heat have on engine power?

Applying carburetor heat results in a noticeable drop in power due to the introduction of warm, less dense air into the engine's fuel-air mixture. Carburetor heat is primarily used to prevent or eliminate carburetor icing, which can occur when moisture in the air freezes in the carburetor. When carburetor heat is applied, it warms the incoming air, which decreases its density and therefore reduces the amount of oxygen available for combustion.

Since the fuel-air mixture becomes less efficient with warmer air—leading to a reduction in overall engine power—pilots often experience a decrease in performance during this process. As the temperature of the incoming air increases, there is less oxygen present, which directly affects the engine’s ability to produce maximum power. Thus, while carburetor heat is crucial for avoiding icing and maintaining engine operation, it typically results in a noticeable power reduction when engaged.