Generators play a vital role in our lives, providing reliable power when we need it the most. From backing up our homes during outages to powering remote construction sites, generators have become indispensable tools. One crucial aspect of generator operation is understanding the various fuel types available and their impact on efficiency, fuel consumption, and performance.

In this article, we will explore generator fuel types in detail, including the generator oil type, the most efficient fuel options, fuel consumption considerations, types of generators, generator fuel delivery methods, gas options, and portable generator oil types.

Generator Oil Type

Generator oil type is a critical factor in maintaining the longevity and performance of your generator. Read our article on how long a generator will last to increase its efficiency and productivity.

Generator Oil Type

The two primary oil types used in generators are conventional motor oil and synthetic oil. Conventional motor oil is suitable for most generators and provides adequate lubrication. However, synthetic oil offers enhanced performance, especially in extreme temperatures and demanding conditions. Synthetic oil provides better viscosity stability, oxidation resistance, and extended drain intervals, making it an excellent choice for high-performance generators that operate in challenging environments.

Most Efficient Fuel for a Generator

Here is the list of different types of fuel according to their efficiency:


Gasoline is the most common fuel used in portable generators due to its wide availability. It offers ease of use and is suitable for small to medium-sized generators. However, gasoline has lower energy density compared to other fuel types, resulting in higher fuel consumption rates and shorter runtimes. It is important to consider the availability of gasoline during emergencies or in remote locations where refuelling may be challenging.


Diesel fuel is renowned for its efficiency and reliability, making it a popular choice for larger, industrial generators. Diesel generators offer better fuel economy and longer runtimes compared to gasoline generators. Additionally, diesel fuel is less volatile and safer to store, making it ideal for long-term power solutions. However, diesel generators may have higher upfront costs, require regular maintenance, and produce more noise and emissions compared to other fuel types.

Most Efficient Fuel for a Generator

Natural Gas

Natural gas is an abundant and cost-effective fuel source, making it a viable option for stationary backup generators. Natural gas generators offer consistent performance, longer runtimes, and reduced emissions compared to gasoline or diesel. However, the availability of natural gas infrastructure is a limiting factor, and the initial setup costs can be higher. Natural gas generators are commonly used in residential, commercial, and industrial applications where a continuous fuel supply is readily available.


Propane is another versatile fuel option for generators. It offers excellent fuel efficiency, longer shelf life, and lower emissions compared to gasoline or diesel. Propane generators are popular for both portable and standby applications. Additionally, propane is readily available in portable tanks, making it convenient for off-grid or remote locations. Propane generators are commonly used in recreational vehicles, camping trips, outdoor events, and residential backup power.

Generator Fuel Consumption

Understanding generator fuel consumption is crucial for managing operational costs and ensuring uninterrupted power supply. Fuel consumption varies based on factors such as generator size, load capacity, and fuel type.

In general, diesel generators are known for their fuel efficiency, followed by natural gas and propane generators. Gasoline generators tend to consume fuel at a higher rate due to their lower energy density. To estimate fuel consumption, refer to the generator’s specifications, which typically provide fuel consumption rates at various load capacities. It’s essential to match the generator’s capacity with the expected load to optimize fuel efficiency and maximize runtime.

Types of Generators

Here is the list of types of generators that you can choose according to your suitability:

Portable Generators

Portable generators are compact and designed for temporary power needs. They are typically fueled by gasoline, propane, or a combination of both. Portable generators are ideal for outdoor activities, construction sites, and for providing power during emergencies. Always refer to the manufacturer’s guidelines for the recommended oil type for your portable generator. The convenience of portability comes with trade-offs in terms of lower power output and shorter runtime compared to larger stationary generators.

Standby Generators

Standby generators are permanently installed and automatically provide power during outages. They are commonly powered by natural gas or propane. Standby generators offer seamless, uninterrupted power supply and are often used in residential, commercial, and industrial applications. These generators are designed to handle higher loads and provide longer runtimes than portable generators. The installation and maintenance of standby generators require professional assistance.

Types of Generators

Diesel Generators

Diesel generators are robust and well-suited for heavy-duty applications. They are commonly used in construction sites, data centres, and industrial facilities. Diesel generators are known for their fuel efficiency, durability, and ability to handle high loads for extended periods. They are often preferred for their reliability, lower maintenance requirements, and longer lifespan compared to gasoline generators. However, diesel fuel may have higher upfront costs and may not be suitable for areas with strict emission regulations.

Natural Gas Generators

Natural gas generators are ideal for stationary backup power applications. They are quieter, cleaner, and emit fewer pollutants compared to diesel generators. Natural gas generators are commonly used in residential and commercial buildings, hospitals, and telecommunications facilities. These generators rely on a continuous supply of natural gas through existing gas lines, eliminating the need for refuelling or storage of fuel on-site.

Generator Fuel Delivery

Generator fuel delivery methods depend on the fuel type and the specific application. Here are the common methods:

Gravity Feed

Gravity feed is suitable for generators with fuel tanks located above the engine level. The fuel flows naturally from the tank to the generator, requiring no additional equipment. This method is commonly used for portable generators and smaller standby generators.

Fuel Pump

Generators with fuel tanks located below the engine level require a fuel pump for proper fuel delivery. The fuel pump transfers the fuel from the tank to the generator, ensuring a constant supply during operation. This method is commonly used for larger standby generators and diesel generators.

Type of Gas for Generators

Natural Gas

As mentioned earlier, natural gas is a popular fuel choice for stationary backup generators. It is a clean-burning fuel that reduces emissions and provides a reliable power source. Natural gas generators are connected to the existing gas lines, ensuring a continuous supply without the need for refuelling. They are commonly used in residential, commercial, and industrial applications where a constant fuel supply is available.

Type of Gas for Generators


Propane is commonly used for both portable and standby generators. It is stored in portable tanks or larger stationary tanks and offers clean combustion, long shelf life, and convenience in terms of fuel delivery and storage. Propane generators are widely used for recreational purposes, residential backup power, and off-grid applications. The availability of propane tanks and refilling stations varies based on the region.

Portable Generator Oil Type

For portable generators, the recommended oil type is typically mentioned in the manufacturer’s guidelines or user manual. The most commonly used oil types are 10W-30 or 10W-40, which provide adequate lubrication and protection for the engine. However, it’s essential to
note that the specific oil type may vary depending on the generator model and manufacturer’s recommendations. It is crucial to follow these guidelines to ensure optimal performance and longevity of the portable generator.

When selecting generator oil, consider factors such as ambient temperature and operating conditions. In colder climates, you may need to use oil with a lower cold-temperature viscosity rating to ensure easy starting and proper lubrication. Conversely, in hotter climates, oil with a higher viscosity rating may be recommended to maintain optimal lubrication under elevated temperatures.

Regular maintenance of the portable generator, including oil changes at the recommended intervals, is essential to keep the engine running smoothly. Ensure that you use high-quality oil that meets the manufacturer’s specifications to maintain optimal performance and protect the generator’s internal components.

Generator Fuel Types – FAQs

How much fuel does a generator use per hour?
The fuel consumption of a generator varies depending on its size and load. On average, a generator can use around 0.5 to 2 gallons of fuel per hour.
How often do you change generator oil?
It is recommended to change the oil in a generator every 100 to 200 hours of operation or at least once a year, whichever comes first.
What type of fuel do generators use?
Generators can use various types of fuel, including gasoline, diesel, natural gas, and propane. The specific type of fuel depends on the generator’s design and fuel compatibility.
How far is the generator from the propane tank?
The distance between a generator and a propane tank depends on local regulations and safety guidelines. However, a common guideline is to keep the generator at least 5 feet away from the propane tank to minimize the risk of fire hazards.
Which type of fuel is used in generators?
Generators can use different types of fuel, such as gasoline, diesel, natural gas, or propane, depending on their design and intended use. The choice of fuel depends on factors like availability, cost, and the specific requirements of the generator.



Selecting the appropriate fuel type for your generator is crucial for ensuring efficiency, performance, and longevity. Factors such as generator oil type, fuel consumption rates, and generator type should be carefully considered based on your specific power needs and operational requirements. By understanding the different fuel options available and their respective advantages and limitations, you can make informed decisions to optimize your generator’s performance and maximize its reliability when it matters most.

Remember to refer to the manufacturer’s guidelines and recommendations regarding fuel type, oil type, and maintenance procedures for your specific generator model. Proper maintenance, including regular oil changes and adherence to fuel guidelines, will contribute to the efficient operation and prolonged lifespan of your generator, ensuring that it remains a reliable power source in times of need.

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