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The 4 Most Common Types of Fuel: Which is the Best Fuel for Your Generator?

One of the most important things to consider when selecting a generator for your home or business is the type of fuel it relies on to run. Most people tend to mistakenly believe that all fuels are the same or that the type of fuel doesn’t matter, but this couldn’t be further from the truth. Different types of fuels can vary substantially in price, availability, and storage requirements based on geographical location; the last of which is especially important to keep in mind, since most fuels are stored at or near the site where the generator is installed.

Diesel, gasoline, propane, and natural gas are the four most common options when it comes to fueling your generator. There is no universal fuel for any given generator, and there are certain pro-versus-con variables pertaining to each of these fuel types that will determine which of these fuels (and consequentially the generators that run on it) are the best fit for your backup power needs. Consider the information provided below before making any major decisions about your residential or commercial generator, or its fuel.



Diesel fuel is among the most common fuel types and is also the most popular. Diesel generators are the most frequently utilized for facilities with high kW appliances, like commercial businesses, and for locations that require a steady supply of power to operate during emergency situations, like hospitals and 911 call centers.


  • Diesel is a very easy fuel source to obtain
  • Diesel generators are the most suitable for long-term use
  • Diesel generators are the least expensive to operate and maintain over time
  • Diesel is the least flammable of the four major fuel sources and can therefore be stored on site for quick and easy refueling


  • Diesel has a shelf life of anywhere between 18 to 24 months
  • Diesel generators produce more engine noise when compared to other generators
  • Diesel is less effective in cold temperatures, so it must be used in combination with another fuel source to power generators located in colder areas


For Generac commercial generators that rely on diesel fuel in order to run, click HERE.



Gasoline, as a fuel source, is likely the easiest to come by. It is suitable for most generators—as long as they produce less than 150 kW of power—and is most commonly used by individuals with residential backup generators. However, the issues of safety and affordability are more prominent with gasoline usage than any other fuel source.


  • Gasoline is the easiest fuel source to obtain
  • Gasoline generators have a very simple fueling process
  • Gasoline is the most suitable fuel source for portable and smaller standby generators


  • Gasoline has a shelf life of only 12 months
  • Gasoline is highly flammable and poses a safety hazard for on-site storage
  • Gasoline is expensive and the demand for it always increases during an emergency
  • Gasoline is the least suitable for cold weather conditions when compared to other fuel sources


To explore your options for a gasoline-fueled generator crafted by industry-leading Generac, click HERE.


Natural Gas

Natural gas is by far the most plentiful source of generator fuel and is frequently used to power entire towns including homes, schools, and businesses. Natural gas is the only fuel source that is distributed to power generators through a local utility grid as opposed to on-site manual fueling. As long as your home or business is connected to this grid, backup power will be supplied in the event of a power outage.


  • Natural gas is abundant and easily obtained
  • Natural gas out-performs all other fuel sources in frigid weather conditions
  • Natural gas is the only generator fuel source that does not require refueling
  • Natural gas promotes long-lasting generator operability and is also the most environmentally-friendly fuel source


  • Natural gas has a lower power output than other fuel sources
  • Natural gas has a higher consumption rate than other fuel types
  • Natural gas is not suitable to provide backup power to earthquake-prone areas, since broken gas lines pose a major public safety hazard


You can look over your options for natural gas residential generators HERE.



Propane is not commonly utilized for commercial or industrial purposes due to the costs and complexities of installing and storing it. However, propane is a great fuel source suited to smaller generators used to supply power to any necessary appliances at home during a power outage.


  • Propane generators produce very little engine noise
  • Propane is a clean-burning and emission-compliant fuel source
  • Propane has a limitless shelf-life and is easy to store onsite for refueling


  • Propane generators have a complicated fuel system
  • Propane storage containers are pressurized and flammable
  • Propane generator installation and maintenance costs can be expensive
  • Propane generators have a high consumption rate and a short life expectancy


To review a list of home backup generators that utilize propane, click HERE.


Each of these four fuel sources (diesel, gasoline, natural gas, and propane) has distinctive uses, benefits, and risks when it comes to being used in a residential or commercial backup generator. While not all of them are best suited for large-scale operations like industrial or commercial businesses, any of these fuel sources can be used for generating backup power at home, so long as the specific safety requirements of each are met. Generac offers a variety of generators suited to all types of landscapes and related safety regulations, and Assurance Power Systems is ready to install, maintain, and repair them for you. If you have any questions about what generator and fuel type is right for you, call us today at

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