What are the benefits of supercharging in terms of density and sea level power?

• A. Density is higher at altitude and higher sea level power than a normally aspirated engine of the same size
• B. Density is lower at altitude and lower sea level power
• C. Density remains the same at altitude; sea level power is unchanged
• D. Density is higher at sea level but lower altitude performance

Answer: (A)

Supercharging increases the density of air entering the engine by compressing it. More dense air means more oxygen for combustion, which lets the engine burn more fuel and produce more power.

At altitude, the surrounding air is thinner, so a normally aspirated engine loses density and power. The supercharger counteracts this by pressurizing the intake air, raising its density above what the ambient air would provide at that altitude, which helps preserve or even boost power.

At sea level, the boosted air can be denser than what a naturally aspirated engine of the same displacement would ingest, so the engine can develop more power than the NA counterpart. That combination—higher density at altitude and higher sea-level power—captures the main benefits of supercharging.