Types of Oil Used in Generators

Oil is an essential component of the generator engine’s operation. It is used in the internal combustion engine to lubricate its parts and reduce friction. Its job is to generate a barrier between the mechanical parts to prevent damaging contact.

Oil cleans components by removing particles that can accumulate inside the engine. It keeps the engine’s parts from rusting and keeps the engine cool by letting parts move more efficiently. But, what type of oil does a generator use, and, more importantly, what type should it use?

Checking and changing your generator’s oil every 100-150 hours of operation is just as essential as changing the oil in your car. This increases your generator engine’s life. When you are not using your generator regularly, start it and let it run for 10-15 minutes at least once per month. This enables the oil to keep the components lubricated and clean even when not in use.

Before going to the store to get oil for your generator, read the owner’s manual to know what oil is advised for your model. However, if you require additional assistance, here are some pointers.

The Different Types of Power Generator Fuel

The fuel source determines the lubricant and oil used in power generators. Based on this criterion, power generators are classified into diesel, gasoline, propane, natural gas, and hydrogen generators.

Gasoline Generators


The most widespread fuel type for various generators, particularly portable and inverter models, is gasoline. Gas generators are frequently inexpensive and simple to operate. As a result, they are an excellent pick for unpracticed users and those on a tight budget. They are also fairly quiet than diesel-powered generators, ideal for working in quieter environments.

One of the most significant drawbacks of gasoline is its short shelf life. Municipalities frequently limit gasoline space to 25 gallons or less. As a result, supplies are frequently depleted during emergencies such as power outages.

It is not shocking that standby generators seldom use gasoline. You can only find it in the RV and portable markets.

Propane Generators

Propane, or liquefied petroleum gas, is a clean-burning fuel with an infinite shelf life. It is more energy-dense than natural gas but less so than gasoline or diesel. Depending on your needs, you can store propane in tanks with capacities ranging from 20 pounds to hundreds, even thousands, of gallons.

Propane generators are widely used in both commercial and residential settings. They can be found in commercial mobile applications, RV trailers, RVs, propane-powered standby generators, campers, and portable generators.

Natural Gas Generators

Natural gas is among the most readily available and cost-effective standby generator fuels. Despite providing less energy than propane, gasoline, or diesel, users prefer it because the fuel supply is limitless. As a result, natural gas is an excellent choice for commercial and residential power generation.

Natural gas generators are more environmentally friendly than gasoline or diesel alternatives. They emit fewer emissions, making them an excellent choice for green businesses and homes.

Another significant advantage of natural gas generators is their durability. They can last for years if properly maintained. They are, however, susceptible to cold climates. You can substantially reduce maintenance costs and extend the life of your natural gas-powered engine by using the proper lubricants and oils.

Hydrogen Generators

Hydrogen generators are still in their infancy, and as such, they are difficult to come by. They run on hydrogen gas and have inbuilt fuel cells to boost the system’s fuel efficiency. They are ideal for organizations such as hospitals that require a continuous power supply. You can also use them in homes and remote locations.

Durability, high power output, and sturdiness are advantages of using a hydrogen generator. These features, however, come at a higher cost.

Diesel Generators


Because diesel generators are less volatile than gasoline generators, they are more affordable and efficient. Portable small diesel generators, commercial backup generators, residential home backup generators, commercial mobile generators, light towers, and trailered mobile generators can all be powered by diesel.

However, keep in mind that regular diesel fuel can cause the generator’s functions to fail. Diesel generators can endure low temperatures if they are endowed with winter diesel fuel.

Choosing the Best Generator Lubricants and Oils

Whether industrial, commercial, or residential, knowing the type of generator you have is only half the battle. The other half is selecting the appropriate lubricants and oils. There are several factors to consider, and here are a few of them.

Viscosity of Oil

When selecting generator oil, the most important factor to consider is viscosity. It denotes the oil’s resistance to shear and flow. Many factors influence oil viscosity, including particle contamination, water contamination, and the overall age and shape of the engine.

The generator’s temperature has a significant impact on the oil’s viscosity. Always check the OEM’s specifications before buying lubricants with the optimal viscosity index. Several criteria, such as ambient temperatures, recommend viscosity grades.

Every type of generator oil has its label, like 5W-20. The first number in the code indicates how well you can pump the oil at low temperatures. The letter W stands for the engine’s base temperature. The second number indicates whether the oil is resistant to thinning at normal operating temperatures or high temperatures.

Consider the Temperature


As previously stated, the temperature of the generator affects the viscosity of the oil. For example, if you intend to use the generator in freezing temperatures, you will require oil types to withstand the conditions. In that case, generator oil with a lower first number, like 5W-30, is required. It improves your generator’s performance in temperatures as low as -28°C.

You should use a multi-grade oil with a higher second number, like 15W-40 oil, when operating in high temperatures. Even at higher temperatures, the lubricant flows way quicker through the engine than pure SAE 40.

Most gasoline engines have viscosity grades of 5W-20, 5W-20, and 0W-20, whereas diesel engines have viscosity grades of 5W-40 and 15W-40. By using the appropriate viscosity index oil, you can extend the life and durability of your power generator.

Valvoline offers a variety of lubricant and oil formulas to meet your needs.

Using Synthetic vs. Standard Oils

Another concern about generator lubricants and oil is using standard or synthetic oil. Synthetic lubricants and oils benefit your generator in a variety of ways.

To begin, synthetic oils are created by breaking down and rebuilding petroleum molecules. This process helps create a more homogeneous molecular structure, minimizing power consumption and increasing efficiency. Synthetic lubricants, unlike mineral oils, contain fewer contaminants and impurities.

Synthetic oils have a higher viscosity index, improve generator maintenance, and save energy. They are also far more stable than mineral oils, critical in harsh working conditions.