Supercharging primarily helps by compensating for decreased air density at altitude, enabling performance similar to sea level.

• A. By increasing charge density to compensate for altitude air density loss.
• B. By decreasing fuel consumption at all times.
• C. By removing the need for lubrication.
• D. By increasing exhaust temperatures.

Answer: (A)

When altitude reduces air density, the engine gets less oxygen per intake stroke, so it can’t burn as much fuel and loses power. A supercharger fixes this by compressing the incoming air, increasing the density of the air charge that enters the cylinders. With a denser charge, more oxygen is available for combustion, so more fuel can be burned and engine power is restored toward what you’d expect at sea level. That’s why the statement about increasing charge density to offset altitude air density loss is the best description of what a supercharger does.

The other ideas aren’t the primary purpose: reducing fuel use at all times isn’t the goal, lubrication isn’t eliminated by supercharging, and while combustion can affect exhaust temperature, increasing exhaust temperatures isn’t the mechanism by which altitude power is maintained.