Which device increases engine performance by increasing the amount of air delivered to the engine?

• A. Increases exhaust gas temperature
• B. Increases air delivered to the engine
• C. Reduces engine displacement
• D. Increases fuel consumption

Answer: (B)

Increasing the amount of air entering the engine boosts combustion energy and, therefore, engine power. More air means more oxygen is available to burn with fuel, so the engine can produce more power. A device that increases air delivery—such as forced induction or an enhanced intake system—directly raises the air supply to the cylinders, which is why this option best describes how to improve performance.

The other ideas don’t raise power by increasing air delivery: higher exhaust gas temperature reflects exhaust conditions after combustion, not the intake of air; reducing engine displacement lowers the maximum air the engine can draw in; and simply increasing fuel consumption without more air won’t yield more power and can reduce efficiency.