Brake Specific Fuel Consumption Calculator

Calculate BSFC from measured fuel flow and power output per SAE J1312 test procedure for engine efficiency mapping.

Input Parameters

Results

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BSFC
g/kWh
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BSFC
lb/hp-hr
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Brake Thermal Eff
%
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Est. Fuel Economy
mpg
Note: Best BSFC for SI engines is typically 230-260 g/kWh at mid-speed, high-load. Diesel engines achieve 195-220 g/kWh. SAE J1312 defines fuel consumption test methods.

Reference

BSFC = Fuel_flow (g/hr) / Power (kW) BSFC (lb/hp-hr) = BSFC (g/kWh) × 0.001644 Brake Eff = 3600 / (BSFC × LHV) Power = Torque × RPM × 2pi / 60 / 1000