Carburetor heat at full throttle decreases engine RPM by which range?

Carburetor heat at full throttle decreases engine RPM by which range?

• A. 100-125 RPM
• B. 200-250 RPM
• C. 50-100 RPM
• D. 150-200 RPM

Answer: (D)

Carburetor heat introduces heated air into the induction system, which lowers the density of the air entering the engine. With less dense air at the same throttle setting, the engine draws fewer mass units of air, and the fuel metering is not adjusted correspondingly, so the engine loses some power. At full throttle on a Cessna 152, that loss shows up as a noticeable RPM drop, typically in the range of 150 to 200 RPM. After a moment, as the system and engine warm and the air becomes more uniform, the RPM stabilizes. The exact amount can vary with temperature, engine condition, and altitude, but 150–200 RPM is a common expectation.

Carburetor heat introduces heated air into the induction system, which lowers the density of the air entering the engine. With less dense air at the same throttle setting, the engine draws fewer mass units of air, and the fuel metering is not adjusted correspondingly, so the engine loses some power. At full throttle on a Cessna 152, that loss shows up as a noticeable RPM drop, typically in the range of 150 to 200 RPM. After a moment, as the system and engine warm and the air becomes more uniform, the RPM stabilizes. The exact amount can vary with temperature, engine condition, and altitude, but 150–200 RPM is a common expectation.