Brake Specific Fuel Consumption (BSFC) expresses fuel consumption as what unit?

Brake Specific Fuel Consumption (BSFC) expresses fuel consumption as what unit?

• A. per hour
• B. per minute
• C. per second
• D. per horsepower-hour

Answer: (D)

BSFC expresses how much fuel is used to produce a given amount of power over time. It is the fuel flow rate divided by the engine’s brake power, so the units are mass per time per unit of power: pounds per horsepower-hour (lb/(hp·h)). In other words, it tells you how many pounds of fuel are needed to generate one horsepower for one hour. This is why the standard unit is per horsepower-hour; it combines fuel flow with the actual power produced. In SI units, you’d see kilograms per kilowatt-hour.

BSFC expresses how much fuel is used to produce a given amount of power over time. It is the fuel flow rate divided by the engine’s brake power, so the units are mass per time per unit of power: pounds per horsepower-hour (lb/(hp·h)). In other words, it tells you how many pounds of fuel are needed to generate one horsepower for one hour. This is why the standard unit is per horsepower-hour; it combines fuel flow with the actual power produced. In SI units, you’d see kilograms per kilowatt-hour.