Brake-specific fuel consumption (BSFC)

Brake specific fuel consumption is fuel mass burned per unit brake (shaft) energy, $BSFC = \dot m_f / P_b$, normally in g/kWh. Modern large two-strokes reach about 165 to 175 g/kWh at the best point; medium-speed engines sit higher. Because it references brake power, BSFC already nets out mechanical friction. It is corrected to a reference fuel calorific value for comparison, and it ties directly to CO2 emission factors and the EEDI and EEXI power terms.