How Much Gas Do Portable Generators Use?

  • By: Umer.A
  • Date: October 10, 2021
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A 5-kW generator consumes 0.75 gallons of gasoline in an hour. So, you should get enough gasoline to last for more than a day.

If a storm is raging in your residential area, you can expect power outages for a long time. A power outage may last from 12 hours to 2 days. You should prepare yourself for at least 24-hours. You must know how much fuel you require to run your portable generator. We have jotted down our research to help you with this.

What Type of Generator Do You Have?

To find out what type of generator you own, you can start by looking for the model number. Some generators have these numbers engraved on the rocker covers. They can be located on either the left or the right side of the cover. If yours doesn’t have the model number, you can look for it on the fuel tank. On a fuel tank, the number is there on a label.

Once you find out your generator’s model number, you can contact the manufacturer and tell them the number. They will tell you what type of generator you have; conventional or an inverter generator. And whether it uses gasoline or diesel.

Diesel Generator Fuel Consumption:

Diesel generators are famous for their high-power output. They are suitable for remote applications or emergencies that require constant backup. Overall, a diesel generator costs more than other generators. This is mainly because of their engine’s liquid cooling.

You might want to estimate your generator’s consumption. An 8-kW diesel generator consumes up to 16.5 gallons of fuel in a day. This is lower than a gasoline generator. Diesel generators are effective. But overall, they are more costly than other types.

Propane Generator Fuel Consumption:

A propane generator consumes a high amount of fuel than other types of generators. If you plan to use it for backup purposes, getting a larger tank would be better.

A 20-kW generator consumes approximately 2-3 gallons of propane per hour. This is a tentative estimate according to the condition of your generator. The average consumption can be higher.

What Kind of Gas Does A Generator Use?

A generator uses different types of fuel to generate electricity. The common types of fuel are diesel, gasoline, and propane. Over the years, generators have advanced, and now, they support two or three fuels. Many generators on the market can run on two different fuels; gasoline or propane. They are called the Bi-Fuel or Hybrid generators.

After the invention of the Bi-Fuel generators, the manufacturers questioned among themselves if that was the end. They started testing for a newer type of generator. These generators could run at three different types of fuels.

If you plan on using gasoline, generators usually use a regular grade #87 octane gasoline. To obtain high efficiency, it must be clean, unleaded, and fresh gasoline.

Technicians suggest using a non-ethanol-premium fuel. But, you up-to 10% ethanol is acceptable. If you are planning to modify your portable generator’s engine. So, it can run on alternate fuels and may reduce the longevity of the engine.

What Kind of Gas Does A Generator Use

What Affects Generator Gas Consumption Rates?

If your generator is consuming too much gas, there may be different factors affecting it. It can be because of the fuel quality you are using in your generator. The fuel is not good if it has a lower octane level than required by your generator’s engine. Your generator won’t be able to burn it properly and give off black smoke. This black smoke shows that the fuel isn’t combusting properly.

Another reason is the engine oil’s maintenance. It is a common mistake because most portable generator owners neglect it. If you are using worn-out engine oil, it won’t lubricate your generator’s internal parts properly. It can affect the efficiency of the generator. But it is limited by mechanical failure to generate the target voltage.

If you have added an air conditioner to the home grid, your generator will increase its fuel consumption. This is because of the extra load you put on it. If you are putting up 50% of the generator’s wattage, it will consume lesser fuel. But if you put up 100% load, the generator will consume more fuel. Your generator’s internal parts will wear out by it too.

Which Fuel Type Is Best?

To buy a generator, you might want to consider things other than its output or durability. Fuel also plays a vital role in the generator’s productivity. Generators use four common fuel types. They are diesel, gasoline, natural gas, and propane.

Diesel is a common type of fuel that is widely available. Diesel generators are for long-term plans. They are used to operate during emergencies, such as 911 call centers or hospitals. Their engine produces a loud noise. And they become less effective in colder temperatures.

Gasoline is for generators that generate comparatively lower output. They are usually for residential houses or as smaller standby generators. But gasoline is flammable and more expensive than other types.

Natural Gas is the widely used source of fuel in generators. It has a dedicated supply grid that can be used in emergencies. Gasoline generators have lower output yet higher consumption rates than others.

Propane is for smaller generators to power necessary appliances at home. They produce little engine noise and are environment friendly. They have complicated fuel systems and are stored in pressurized containers. Propane generators have high consumption rates. Compared to other generators, they have a short life expectancy.

How Long Will A Generator Run On 5 Gallons Of Gas?

Every generator has a different run time, which depends upon the load and size of the generator. If there isn’t a higher load, the generator will run for a longer time. But on average, 5 gallons of gas will last up to 8 hours.

How Much Gas Does A Generator Use In A Day?

It depends on the generator’s size on how much a generator will use in a day. If you own a 5-kilowatt gasoline generator, it will consume up to 18 gallons in a day.

How Much Gas Does A Generator Use Per Hour?

A typical 5-kilowatt portable generator consumes 0.75 gallons per hour. This can vary depending on the output it produces.

Is It Better to Store A Generator with Or Without Gas?

If you are planning to store your generator for a long period. Then it is best to store it without gasoline.


There you have it. We hope now you have a better idea of your generator’s consumption. You should properly maintain your generator. If it isn’t maintained, fuel consumption would be highly anticipated. Change its engine oil and fuel filters to increase its efficiency.