How to Calculate Fuel Consumption From Bsfc

What is Brake Specific Fuel Consumption (BSFC)?

Brake Specific Fuel Consumption (BSFC) measures the amount of fuel consumed per unit of brake power output. It's expressed in grams of fuel per kilowatt-hour (g/kWh) and provides insight into an engine's efficiency.

BSFC is calculated by dividing the total fuel consumed by the total brake power output over a specific period. Lower BSFC values indicate better fuel efficiency.

How to Calculate Fuel Consumption from BSFC

To calculate fuel consumption from BSFC, you need to know the engine's brake power output and the corresponding fuel consumption rate. Here's the step-by-step process:

1. Determine the engine's brake power output in kilowatts (kW).
2. Measure the total fuel consumed in grams over the same period.
3. Use the BSFC formula to calculate the fuel consumption rate.
4. Interpret the result in the context of your engine's specifications.

The calculator on this page automates these steps for quick and accurate results.

BSFC Formula

The formula converts the fuel-to-power ratio to grams per kilowatt-hour, which is the standard unit for BSFC.

Worked Example

Let's calculate BSFC for an engine that consumes 500 grams of fuel while producing 20 kW of brake power:

This means the engine consumes 25 grams of fuel for every kilowatt-hour of brake power output.

For comparison, a typical diesel engine might have a BSFC of around 200-250 g/kWh, while a gasoline engine might be in the 250-350 g/kWh range.

Factors Affecting BSFC

Several factors influence BSFC, including:

• Engine Load: Higher loads typically result in lower BSFC values.
• Fuel Type: Different fuels have different energy densities.
• Engine Efficiency: Well-tuned engines generally have lower BSFC.
• Operating Conditions: Temperature and humidity can affect results.

Understanding these factors helps in interpreting BSFC results and optimizing engine performance.