What is the purpose of carburetor heat?

The purpose of carburetor heat is to prevent ice formation in the carburetor. As ambient air passes through the carburetor, it can cool significantly, especially in conditions of high humidity or low temperatures. When moisture in the air freezes, it can form ice within the carburetor, leading to restricted airflow and fuel delivery, which may result in engine roughness or even stalling.

Applying carburetor heat draws warm air from around the engine into the carburetor, raising the temperature and preventing ice formation. This is particularly critical during the pre-flight checklist and when operating in conditions conducive to carburetor icing. Keeping the carburetor free from ice ensures smooth engine operation and enhances safety in flight.

In contrast, while high altitudes and improved fuel efficiency might seem beneficial, carburetor heat is not primarily designed for those purposes. It also does not directly correlate to increased power during takeoff; rather, it focuses on maintaining optimal function of the fuel-air mixture by preventing potential icing issues.