Estimate and visualize engine SFOC (g/kWh) versus load. Supports interpolation and curve plotting.
Estimated SFOC: — g/kWh
Change vs 100% MCR: — %
Specific Fuel Oil Consumption (SFOC) is a fundamental performance indicator used to describe the efficiency of marine diesel engines. It expresses the mass of fuel consumed per unit of useful energy produced and is typically measured in grams per kilowatt-hour (g/kWh).
SFOC represents how efficiently an engine converts fuel energy into mechanical output. Lower SFOC values indicate higher efficiency and lower operating costs. Engine manufacturers usually provide SFOC curves as a function of engine load, measured during shop or sea trials.
In real operation, engines rarely run exactly at 100% MCR. Therefore, estimating SFOC at part load is essential for realistic fuel consumption calculations.
This tool estimates SFOC at a given engine load using a smooth interpolation based on the reference SFOC at 100% MCR. Adjustable coefficients allow the curve shape to be tuned to match typical low-load penalties observed in medium-speed and slow-speed marine engines.
The general form reflects common engine behavior:
Engine SFOC is not constant across the operating range. Changes in fuel injection timing, scavenging efficiency, and combustion quality cause measurable variation with load.
By plotting SFOC against engine load, operators and engineers can identify optimal operating points and evaluate the fuel penalty of slow steaming or part-load operation.
SFOC is a key input for total fuel consumption calculations. Once engine power and operating time are known, fuel consumption is obtained by multiplying energy output (kWh) by SFOC and converting grams to tonnes.
Accurate SFOC estimation significantly improves the reliability of voyage fuel predictions compared to using fixed consumption rates.
This calculator provides an engineering estimate. Actual SFOC depends on engine condition, fuel quality, ambient conditions, and tuning. For contractual or compliance use, always refer to certified engine test data and onboard performance records.