Generator Fuel Consumption

There are several types of fuel used by generators which include gasoline, diesel, propane, and natural gas. Which is best, cleanest burning, most economical etc? This article will look at generator consumption of different types of fuels. Keep in mind that fuel consumption will also vary based on variables such as brands, load, and climate. A generator load calculator may help with gathering more accurate data. At any rate, the information which follows is an “average-based” assessment.

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Consumption Rate Overview


Generac 6000 Review


Honda Parallel Generator


Pro Series Diesel Generator




Consumption: 3.44 GPHConsumption: 0.75 GPHConsumption: 2.9 GPH

Cost: $$$

Cost: $$$

Cost: $$$$

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Gasoline Generator Fuel Consumption:

GeneraciX2000Gasoline is a common source of fuel and easiest to obtain, however, it is highly flammable and unsafe to store in large amounts. Gasoline prices are somewhat expensive and tend to be the least efficient way to run a generator; at least for long periods of time.

Most portable generators will run on gasoline out of  convenience. A standard 5,000 watt generator will consume around 18 gallons of gasoline during a 1 day/24 hour period. This makes it very unrealistic and expensive for long term use. This is why more and more are turning to inverter generators. Most of these offer an eco or economy mode which varies throttle (and ultimately fuel consumption) based on load demands. These are the most efficient gasoline generators. Usually one tank a fuel, which may only be 1-2 gallons, will last 8-10 hours. Therefore, running two inverter generators, which are usually 2,000-4,000 watt power source together, are usually more efficient than running a larger 5,000+ watt open frame generator. Again, this come back to the presence of economy mode as well as the technology/process that produces energy.

Most Efficient Portable Gas Generators



Yamaha Portable Generator


Honda Parallel Generator


Generac iQ 2000 Portable Marine Generator


WEN Generator For Travel Trailer

Most Popular 

Most Reliable



51.5dB at 1/4 load
53db at 1/4 load
1600 running/2000 starting watts
51 decibels at 1/4 load
10.5 hours runtime on 1/4 load
Runs 8.1 hours at 1/4 load
7.7-hour runtime at 1/4 load
6 hours runtime at half load
44 pounds
47 pounds
46 Pounds
48 pounds

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Diesel Generator Fuel Consumption:

There are not many generators that use diesel fuel, but the ones that do are a bit more efficient than gasoline. Diesel is less flammable than other fuel sources, and less expensive to operate. To give you an idea of consumption for the diesel generator, a 20 kilowatt unit will use about 1.6 gallons per hour running a full load. A 30 kilowatt unit will use about 2.9 gallons per hour also running a full load. Most diesel generator applications are meant for job sites, emergency back up generators or are permanently installed on larger diesel pusher RVs.

Propane Generator Fuel Consumption:

Generac 6000 ReviewPropane generator fuel usage is among the most environmentally friendly. Propane has a long shelf life, is clean burning, and easily stored in small or large tanks. Better yet, home delivery is available which makes it even easier and convenient. Propane is burned more quickly. For example, a 20 kilowatt unit would burn about 3.44 gallons per hour, and a 35 kilowatt unit would burn 6.1 gallons per hour.

The biggest drawback to a propane generator from a practical stance is the bottle capacity. One standard propane bottle might be used up in a full day’s use. Therefore, those that have a propane generator often have two or maybe even three reserve tanks if they plan to be off the grid for a longer duration of time. Those that regularly engage in camping and outdoor activities may tend to care more about their impact on the surrounding environment. Using a propane generator is one way to reduce the carbon footprint of a camping trip. This is also why many indoor forklifts use propane or are electric due to low to no emissions.

Natural Gas Generator Fuel Consumption:

Generac Home GeneratorMany homes are already equipped with a tank for a supply of natural gas. Therefore, this makes natural gas a highly convenient way to fuel your generator. Like propane, natural gas is easy to store and can be delivered right to your door. Practically speaking, when considering Nat Gas generators for your home, it would be tied into an already existing application. At full load, a 20 kilowatt unit would use about 289ft³/hour. A 30 kilowatt unit would use about 416ft³/hour at full load.

Depending on your intended use of a generator; you will need to factor in all of the information given to make your decision. The type of fuel you decide to use will narrow the choices you have when it comes to purchasing a generator.

Multiple Fuel Generator Choices: