Brake-specific fuel consumption

Brake-specific fuel consumption (BSFC) is a measure of the <a href="/facts/Fuel_efficiency/URhdQ7Wl">fuel efficiency</a> of any prime mover that burns fuel and produces rotational, or shaft power. It is typically used for comparing the efficiency of <a href="/facts/Internal_combustion_engines/Ju4BXzj0">internal combustion engines</a> with a shaft output.
It is the rate of <a href="/facts/Fuel/H8DIRL1j">fuel</a> consumption divided by the <a href="/facts/Power_(physics)/mkaEyRnn">power</a> produced. 
In traditional units, it measures fuel consumption in pounds per hour divided by the <a href="/facts/Brake_horsepower/jRMwmIxA">brake horsepower</a>, lb/(hp⋅h); in <a href="/facts/SI_units/S7YLglNz">SI units</a>, this corresponds to the inverse of the units of <a href="/facts/Specific_energy/zVRhSxPh">specific energy</a>, kg/J = s2/m2.
It may also be thought of as power-specific fuel consumption, for this reason. BSFC allows the fuel efficiency of different engines to be directly compared.
The term "brake" here as in "<a href="/facts/Brake_horsepower/jRMwmIxA">brake horsepower</a>" refers to a historical method of measuring torque (see <a href="/facts/Prony_brake/V6PV3UxT">Prony brake</a>).

Brake-specific fuel consumption open-in-new

Brake-specific fuel consumption