If you have a diesel generator, you’ll want to know how much fuel you’ll need to power it. We’ve provided an approximate diesel fuel consumption chart below based on the size of the generator in kilowatts (kW) and the generator’s load. The larger the generator and the greater the load, the more fuel you’ll need.
Disclaimer: This table is intended to be used as an estimate of the amount of fuel a diesel generator uses during operation and is NOT an exact representation due to other various factors that may affect fuel usage.
Diesel Fuel Consumption Chart
| Generator Size (kW) | >1/4 Load (gal/hr) | >1/2 Load (gal/hr) | >3/4 Load (gal/hr) | >Full load (gal/hr) |
| 20 | 0.6 | 0.9 | 1.3 | 1.6 |
| 30 | 1.3 | 1.8 | 2.4 | 2.9 |
| 40 | 1.6 | 2.3 | 3.2 | 4.0 |
| 60 | 1.8 | 2.9 | 3.8 | 4.8 |
| 75 | 2.4 | 3.4 | 4.6 | 6.4 |
| 100 | 2.6 | 4.1 | 5.8 | 7.4 |
| 125 | 3.1 | 5.0 | 7.1 | 9.1 |
| 135 | 3.3 | 5.4 | 7.6 | 9.8 |
| 150 | 3.6 | 5.9 | 8.4 | 10.9 |
| 175 | 4.1 | 6.8 | 9.7 | 12.7 |
| 200 | 4.7 | 7.7 | 11.0 | 14.4 |
| 230 | 5.3 | 8.8 | 12.5 | 16.6 |
| 250 | 5.7 | 9.5 | 13.6 | 18.0 |
| 300 | 6.8 | 11.3 | 16.1 | 21.5 |
| 350 | 7.9 | 13.1 | 18.7 | 25.1 |
| 400 | 8.9 | 14.9 | 21.3 | 28.6 |
| 500 | 11.0 | 18.5 | 26.4 | 35.7 |
| 600 | 13.2 | 22.0 | 31.5 | 42.8 |
| 750 | 16.3 | 27.4 | 39.3 | 53.4 |
| 1000 | 21.6 | 36.4 | 52.1 | 71.1 |
| 1250 | 26.9 | 45.3 | 65.0 | 88.8 |
| 1500 | 32.2 | 54.3 | 77.8 | 106.5 |
| 1750 | 37.5 | 63.2 | 90.7 | 124.2 |
| 2000 | 42.8 | 72.2 | 103.5 | 141.9 |
| 2250 | 48.1 | 81.1 | 116.4 | 159.6 |
How To Determine a Generator’s Fuel Consumption
There are additional factors that can affect your generator’s fuel consumption. These include the brand, the generator’s life span, the size of the generator, the load amount, the number of items that need to be powered by the generator, and how well it is maintained.
Portable generators, for example, may be able to provide power generation for one or two tools at a time, while larger standby generators provide power to homes, businesses, and even hospitals.
The size of your fuel tank is important because the more load you apply on the generator, the more fuel you will need.
Generator Loads and Load Settings
When deciding what size generator to use, you should know what you need it to power and how many watts you will need to run it. The amount of power a generator can produce is rated in watts. It is recommended that the generator should never be operated at maximum power for more than 30 minutes at a time.
To determine how many watts you’ll need from your generator, add up all the wattage you’re likely to use at a time. If you’re using your generator to provide a power supply for your home during a power outage, take into account the reactive load of each appliance you start, not just the amount of power it takes to keep them all running.
Appliances with resistive load take less power to start up. They include things like toasters, coffee makers, and televisions. By contrast, appliances with reactive loads — such as air conditioners, refrigerators, air compressors, and high-powered tools like saws or drills — may take up to three times more power to start than it takes to keep them running. Most items with reactive load contain an electric motor.
It’s important to keep the reactive load in mind when adding up the wattage you’ll need to power everything that’s likely to be running concurrently. Add the start-up wattage, not the running wattage, for each appliance with a reactive load when you’re determining the total amount of power you’ll need from your generator.
It’s important to choose a generator that will give you more power than all your appliances or tools added together, in case you end up using more power than you expected. It’s always easier (and cheaper) to have more wattage than you need than to wind up not having enough — and needing to buy a new generator or a second generator to augment the power your original unit provides.
Download our FREE generator rental guide e-book today!
Diesel Generator Rentals
If you are looking for a new generator to rent, please contact us. BigRentz provides towable diesel generators. Power capacities range from 20 kW to 240 kW, with rental prices for 20, 36, and 56 kW models at a little over $100 a day, $345 to $517 a week, and around $900 to a little under $1,100 a month.
Set your jobsite location for the most accurate rates, and request a quote for other models (48, 100, 120, and 240 kW).
