Power and Performance III Tuners Practice Test

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.