What makes exhaust driven turbochargers more efficient than mechanically driven superchargers?

• A. They use energy contained in the exhaust gas that would otherwise be wasted.
• B. They rely on electrical energy from the aircraft's battery.
• C. They operate without any energy input.
• D. They eliminate the need for air intake cooling.

Answer: (A)

Exhaust-driven turbochargers are more efficient because they recover energy that would otherwise be wasted in the engine’s exhaust. The exhaust gases flow through a turbine that drives a compressor, so the boost comes from energy already produced by the engine but not used for propulsion. This means more air is forced into the cylinders without taking power directly from the crankshaft, reducing the engine’s parasitic load compared to a powered supercharger. A mechanically driven supercharger draws power from the engine via a belt or shaft to run the compressor, which reduces net engine output and lowers overall efficiency. By leveraging the waste energy in the exhaust, turbochargers provide boost with less direct power cost to the engine, making them more efficient overall.