Best Oil for Generator: Complete Review

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Written By John Gibbs




» Equipment » Generators » Best Oil for Generator: Complete Review

Generators are a vital part of our lives, providing us with power when we need it most. That’s why it’s important to choose the right oil for your unit, to ensure it runs smoothly and efficiently.

In this article, we’ll take a look at the generator oil type options on the market and provide a complete review of each one. We’ll also discuss some of the key factors to consider when choosing the right oil.

What is a Power Generator?

A power generator is a machine that converts mechanical energy into electrical energy. This conversion is usually done using a diesel engine or a gas turbine. The mechanical energy is usually supplied by a rotating shaft that is turned by an external source, such as an engine or a turbine. The electrical energy produced by the generator is then typically used to power electric motors or to charge batteries.

Gasoline Portable Generator

Power generators are used in a variety of applications, including in emergency situations where backup power is needed, in industrial settings where electricity is required for production, and in recreational settings such as camping or boating where portable power is desired.

Why Does the Generator Need Oil?

The oil in a generator serves two purposes. First, it lubricates the engine. This is important because the engine has a lot of moving parts. The oil helps to keep these parts moving smoothly and prevents them from grinding against each other and wearing out.

Second, the oil helps to keep the engine cool. The oil helps to dissipate the heat that is generated by the engine as it runs. This is important because the engine can get very hot, and if it gets too hot, it can be damaged.

So, it will help to keep your generator running smoothly and prevent it from being damaged.

Portable Gasoline Inverted Generator

What happens if you do not change the oil in the generator in time?

The generator will not be able to function properly. The oil is used to lubricate the engine and keep it cool. If the oil is not changed, the engine will overheat and eventually break down.

What is the difference between oil for different types of generators?

There are many types of generators, and each type requires a specific type of oil. For example, a diesel generator requires a different oil than a gas generator. The best oil for a portable generator must be able to withstand high temperatures and pressures and must be able to lubricate the engine components. It must also be able to protect the engine from rust and corrosion.

The oil for a diesel generator is typically thicker and more viscous than the oil for gasoline. A gasoline generator is typically thinner and less viscous than a diesel. The type of oil used is important because it can affect the performance of the unit.

Portable Diesel Generator

What do you need to know about generator oil?

Generator oil is made from a special blend of oils that are designed to protect your unit from wear and tear. This also helps to keep your backup power cool and prevents it from overloading.

  • The oil needs to be changed regularly. Depending on how often you use your generator, you may need to change it as often as every three months.
  • Be sure to use the proper type of oil. Using the wrong type can damage your generator and void your warranty.
  • If you are unsure about what type of oil to use in your generator, consult your owner’s manual or the manufacturer.
  • Once you have changed, be sure to dispose of the old oil properly. Do not pour it down the drain or put it in the trash. Take it to a local recycling center that accepts oil products.
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Best Generator Oil – Our Top Picks

1. Briggs & Stratton SAE 5W-30 Synthetic Oil

Key Features

  • Viscosity: 5w-30
  • Brand: Briggs & Stratton
  • Liquid Volume: 32 Fluid Ounces
  • Package Information: Bottle

It is a great choice for your generator for several reasons. First, it is a high-quality oil that will keep your engine running smoothly. Synthetic oil is more expensive, but it is worth the investment because it holds its viscosity and does not thicken up when cold or thin when hot.

This also has better thermal stability and oxidation stability than regular oil, and it will provide better deposit control and wear control.

Change it every 25 hours of operation or sooner if you want to eliminate any contamination from the regular oil that may be left behind.

The Briggs & Stratton SAE 5W-30 Synthetic Oil is a great choice for your generator. It is a high-quality oil that will keep your engine running smoothly and extend the life of your generator.

  • High-quality
  • Better thermal stability
  • Better deposit control
  • More expensive than regular oil

2. Honda 08207-10W30 Motor Oil

Key Features

  • Viscosity: 10w-30
  • Brand: Honda
  • Liquid Volume: 1 Quarts
  • Package Information: Bottle
  • Vehicle Service Type: ATV, UTV

This oil has been designed by Honda specifically for its 4-stroke engines. It is a unique blend of base stocks and additives that help to resist viscosity and thermal breakdown. This oil also meets or exceeds all requirements for the API service classifications SM.

This oil will be most beneficial to those who own Honda power equipment. This includes their lawnmowers, generators, and other similar tools.

The only downside to this oil is that it is more expensive than some of the other options on the market. However, it is important to keep in mind that this oil has been specifically designed for Honda engines.

Top-quality motor oil provides excellent protection for your engine and is engineered to resist viscosity and thermal breakdown. This oil exceeds all requirements for API service classifications SM and is the perfect choice for use in your Honda generator.

  • Formulated to protect engines
  • Contains a unique blend of expensive sheer-stable polymer additives
  • Resists viscosity and thermal breakdown
  • Suitable for use as a lubricant in all-new Honda power equipment
  • Price

3. Generac Full Synthetic Motor Oil 5W-30 SP

Key Features

  • Viscosity: 5W-30
  • Brand: Generac
  • Liquid Volume: 32 Fluid Ounces
  • Package Information: Bottle

We all know how important it is to change the oil in our generators, but sometimes we are unsure of what to use. There are many different types and brands on the market, so it can be difficult to choose the right one for your generator. However, we think the Generac Full Synthetic Motor Oil 5W-30 SP is a great option for many generators.

This is made with a high-quality synthetic base and is fortified with an advanced additive. This combination provides a longer engine life and maximum protection against viscosity breakdown. Additionally, the oil protects against the formation of sludge and varnish deposits. It also meets the API SN service classification requirement, so you can be sure it is a high-quality oil.

Some users have said that this oil is a bit more expensive than others on the market. However, we think the longer engine life and other benefits are worth the extra cost.

We recommend this product. Many users have been happy with this oil, saying that it works well in their generators and helps to keep the engine running smoothly.

  • Longer engine life
  • Maximum protection against viscosity breakdown
  • Protects against the formation of sludge and varnish deposits
  • Meets the API SN service classification requirement
  • A bit more expensive

4. Cummins 3265336 Onan SAE 15W-40

Key Features

  • Viscosity: 15W-40
  • Brand: Cummins Onan
  • Liquid Volume: 32 Fluid Ounces

This has a viscosity of 15W-40, which makes it perfect for use in high-powered generators. It also has a high level of anti-wear protection, which helps to extend the life of your generator.

The only downside to this oil is that it only comes in a 32-fluid-ounce bottle. This may not be enough for some people, especially if they have a large generator.

  • High viscosity
  • Good anti-wear protection
  • It only comes in a 32-fluid-ounce bottle

5. Generac Full Synthetic Motor Oil 5W-30 SN

Key Features

  • Viscosity: 5W-30
  • Brand: Generac
  • Liquid Volume: 32 Fluid Ounces
  • Package Information: Bottle

This is high quality and fortified with an advanced additive, meaning it will last longer and provide maximum protection for your generator. The oil also protects against the formation of sludge and varnish deposits and is recommended for use in all gasoline engines. Plus, it exceeds the API SN service classification requirement.

The Generac Full Synthetic Motor Oil 5W-30 is a great option for those looking specifically designed for generators.

  • Fortified with an advanced additive
  • Longer lasting
  • Maximum protection
  • Protects against the formation of sludge and varnish deposits
  • Recommended for use in all gasoline engines
  • More expensive than similar oils

How to Choose the Right Oil for a Generator – Buyer’s Guide

In this buyer’s guide, we will go over some of the different things you need to consider when choosing oil for your generator.

1. Read the Manual

The manual will have specific recommendations for what type and brand of oil to use. It is important to follow these recommendations, as using the wrong can damage your unit.

2. Consider the type of engine

There are two main types of engines for generators:

1. Two-stroke
2. Four-stroke

Each type of engine requires a different. Two-stroke engines require oil that can be mixed with fuel, while four-stroke engines require a separate oil and fuel system. Rotary engines require a special high viscosity.

3. Consider operating temperatures

Every oil has what’s called a pour point, which is the lowest temperature at which it will flow. If you try to operate your generator at or below the pour point, then it will thicken and can cause serious damage to the engine.

On the other end of the spectrum, you also have to be careful not to exceed the oil’s flash point. This is the temperature at which it starts to break down and can cause engine damage.

4. Check the viscosity

The viscosity is a measure of how thick or thin the oil is. If you use one that’s too thin, it won’t lubricate the engine properly. This can cause increased wear and tear on the engine.

On the other hand, if you use that’s too thick, it can cause the engine to overheat. This can damage the engine and shorten its lifespan. To choose the right viscosity oil for your generator, consult the owner’s manual.

5. Go for reliable brands

It is important to choose a brand that is reputable and that you trust. Doing some research online or talking to friends who own generators can help you narrow down your choices.

6. Consider the required amount of oil and replacement time

You will need to know how much oil your generator takes so that you can purchase the correct amount. You will also need to know how often it will need to be replaced. Many manufacturers will have this information in the owner’s manual.

Synthetic vs. Conventional Oil

Synthetic oil is made in a laboratory from artificially created chemicals. Conventional oil is made from crude oil that is refined in a process that has been used for centuries.

Oil filling

Synthetic type is designed to withstand higher temperatures and stress than conventional oil. It also doesn’t break down as quickly, so it can last longer between changes.

Conventional oil is less expensive than synthetic, but it doesn’t last as long and isn’t designed to withstand the same level of work.

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How often should you change the oil?

Home generators should have their oil changed every 50 to 200 hours of operation.

What’s the best oil to use in a generator?

If you’re looking for the best performance, synthetic oil is the way to go. It can withstand higher temperatures and pressures, which means your generator will run more efficiently. Synthetic also has a longer lifespan than natural, so you won’t have to change it as often.

If you’re looking for a more economical option, natural oil is a good choice. It’s not as heat-resistant as synthetic, but it’s still good for your generator.

Can I use 5W30 instead of 10W30 in my generator?

It is generally safe to use a lower viscosity in an engine than what is recommended. The main reason to use a higher viscosity oil is for fuel economy or cold weather starting. If you are not concerned about fuel economy and your generator starts easily in cold weather, you can probably use 5W30 without any problems.

Is 10W-30 oil good for generators?

10W-30 oil is a great choice for generators. It has a high viscosity rating, meaning it will flow easily and keep your engine well-lubricated. It also has a high flash point, meaning it will withstand high temperatures without burning off.

Should you use synthetic oil in a generator?

It depends on your individual needs and circumstances. However, if you use your generator regularly or live in a hot climate, synthetic oil may be the best choice.

What is the best oil for the generator in winter?

The oil should have a high viscosity to prevent it from thinning out at lower temperatures. It should be able to maintain its properties at high temperatures since the generator will be running at a higher load in winter. For example, a 5W-30 oil type is the most suitable for a generator.


The best oil for a generator is one that is designed for use in high-temperature environments. Synthetic oils are a good choice for this purpose, as they can withstand higher temperatures than conventional.

Whatever you choose, be sure to check your generator’s owner’s manual to ensure that it meets the manufacturer’s specifications.

Thanks for reading! We hope this article was helpful. If you have any questions or comments, please feel free to leave them below.

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About John Gibbs

Hello everyone! My name is John Gibbs. I am 60 years old and have been in the family construction business all my adult life. Construction is not only my profession but also my passion. I know everything about building and repair materials, tools, advanced methods, techniques, and approaches. I will share the same knowledge with you in my articles.

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