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how to calculate diesel generator fuel consumption

In this guide, BISON reveals the secrets of efficient fuel usage and takes you through the detailed steps of how to calculate diesel generator fuel consumption.

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In today’s world, diesel generators are one of the most common sources of power we rely on, especially in emergencies where the regular power supply fails. However, using a diesel generator can be expensive because it requires fuel, and fuel costs can quickly become a large part of the overall operational cost.

Therefore, correctly calculating diesel generator fuel consumption can help reduce overall operating costs and keep your expenses under control. In this guide, BISON reveals the secrets of efficient fuel usage and takes you through the detailed steps of how to calculate diesel generator fuel consumption. It will explain the importance of calculating fuel consumption, the factors that affect fuel consumption, and how to accurately calculate diesel generator fuel consumption.

how to calculate diesel generator fuel consumption

Why should you calculate diesel generator fuel consumption?

Calculating the fuel consumption rate of your diesel generator can provide you with a variety of benefits, such as

  • It helps you develop a proper fueling plan.
  • It helps you decide whether to purchase or rent a diesel generator.
  • It enables you to calculate maintenance schedules.
  • It helps you predict potential fuel shortages.
  • It allows you to choose diesel generators with better fuel efficiency.
  • It enables you to save money by minimizing fuel wastage.

Methods to Calculate Diesel Generator Fuel Consumption

Calculating Diesel Generator Fuel Consumption: There are three primary methods – using the generator’s fuel gauge, a fuel flow meter, or the manufacturer’s specifications. Each method has its own level of accuracy and ease of use.

By understanding these methods, you can accurately estimate the fuel consumption of your diesel generator, and BISON diesel generator manufacturers will help you manage operating costs, plan fuel logistics, and ensure optimal generator performance. Remember, an efficiently running diesel generator is not only cost-effective but also very environmentally friendly.

Using the generator’s fuel gauge

The most straightforward method involves using the fuel gauge on the generator itself. This approach, while simple, may not be the most accurate due to potential gauge inaccuracies. Here are the steps to follow:

    • Note the fuel level in the generator’s tank before starting the generator.
    • Operate the generator as needed.
    • At the end of operations, note the fuel level again.
    • Fuel consumption (L/h) = (end tank level – start tank level) / operating hours

Using a fuel flow meter

For a more precise measurement, consider using a fuel flow meter. This device measures the volume of fuel flowing through a pipe, providing a more accurate fuel consumption rate. Here’s how to use it:

    • Install the fuel flow meter in the generator’s fuel line.
    • Record the meter reading before starting the generator.
    • After using the generator, record the meter reading again.
    • The difference between the two readings will indicate the volume of fuel consumed.
how calculate the fuel consumption of generator

Using BISON diesel manufacturer specifications

The BISON generator manufacturer will provide fuel consumption data for the generator. This information is usually based on the size and load capacity of the generator. This method is usually the most reliable, especially for new generators. The following describes how to calculate fuel consumption using this method:

    • Refer to the BISON generator manual or manufacturer’s specifications for fuel consumption rates (usually in liters or gallons per hour at full load).
    • Multiply this rate by the number of hours the generator will be in operation.

diesel generator fuel consumption chart in litres

BISON provides an approximate table of diesel fuel consumption for BISON diesel generators that takes into account the size and operating load of the generator. This is also applicable to other brands of generators.

It is important to understand that this chart is intended only as a rough guide to generator fuel consumption and is not completely accurate, as there are many factors that can increase or decrease actual fuel consumption.

Generator Size (kW)Fuel Consumption (kg)Fuel Consumption (Liters)
30 kW6.3 kg7.8 L
45 kW9.45 kg11.84 L
50 kW10.5 kg13.1 L
75 kW15.7 kg19.7 L
100 kW21 kg26.25 L
150 kW31.5 kg39.4 L
200 kW40 kg50 L
250 kW52.5 kg65.6 L
300 kW63 kg78.75 L
350 kW73.5 kg91.8 L
400 kW84 kg105 L
450 kW94.5 kg118 L
500 kW105 kg131.2 L

What factors affect the fuel consumption of diesel generators?

Calculating the fuel consumption rate is essential to determine how much fuel you need to power specific machines. Regarding diesel generators, the fuel consumption rate depends on the factors mentioned above, which may result in higher or lower fuel consumption.

Many factors can affect your diesel generator’s fuel consumption rate. Some of the most common include:

  • Size of diesel generator
  • Generator load
  • Engine type
  • Generator speed
  • Age of the generator
  • Generator voltage
  • Fuel type and quality
  • Barometric pressure
  • Elevation
  • Weather conditions


Finally, calculating the diesel generator’s fuel consumption is critical to reducing operating costs and ensuring timely refueling for continuous operation. The best way to calculate depends on the type of diesel generator you use and its available features. Following the tips in this guide, you can accurately determine your diesel generator’s fuel consumption rate and optimize its use.

calculate diesel generator fuel consumption FAQ

The most significant factor is the fuel consumption associated with the various generator sets’ cooling fans and water pumps. For this reason, a 100kW diesel generator will burn more fuel at 10kW than a 10kW diesel generator set.

A diesel generator uses about 7% of its rated generator output. So, a 40kW generator will (40kW*7%) burn 2.8 gallons of diesel per hour.

To determine the fuel usage for every 100 km, take the total fuel consumed in liters, divide it by the distance travelled in kilometers, and then multiply the result by 100.

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