Generally, what is the effect of using carb heat on engine performance?

Using carburetor heat typically decreases engine performance. When carb heat is applied, warm air is introduced into the carburetor to help prevent ice formation in conditions where moisture is present. However, this warm air is less dense than the colder, more oxygen-rich air. As a result, the air-fuel mixture becomes less efficient for combustion because it has a lower overall oxygen content.

This reduction in the air density can lead to a decrease in power output. Pilots need to be aware of this trade-off; while using carb heat is crucial for preventing ice buildup, especially in cold and humid conditions, it comes with the cost of reduced engine performance. That's why pilots typically apply carb heat cautiously and monitor their airspeed and engine performance carefully while managing the carb heat in flight.