4 Best Oil For Generac 22kw Generator & Detailed Buying Guide

4 Best Oil For Generac 22kw Generator [Ranked]

There is no doubt that oil is an essential part of your Generac 22kw generator. However, using the wrong or incompatible oil can damage it. That’s why I singled out four of the best oils for Generac 22kw generator.

  • Your first choice is Generac Full Synthetic Oil 5W-20, which is advised by the manufacturer.
  • For a budget-friendly yet quality option, go for Mobil 1 Extended Performance Full Synthetic Oil 5W-20.
  • If you are looking for engine cleaning and protection, Valvoline Advanced Full Synthetic 5W-20 Oil is great.
  • For the best possible result in every aspect get the Pennzoil Platinum Full Synthetic 5W-20 Oil.

In the next few parts of this article, I will tell you exactly why I decided to pick these oils.

Best Oil For Generac 22kw Generator

To understand what makes these oils so special, let’s look at what qualities they possess.

OilUnique Feature Best For Price
Generac Full Synthetic Motor Oil 5W-20Ensures maximum protection and longer engine lifeRecommended by the manufacturerCheck Price
Mobil 1 Extended Performance Full Synthetic Motor Oil 5W-20Meets the highest industry standards for engine protectionBest Budget-friendlyCheck Price
Valvoline Advanced Full Synthetic SAE 5W-20 Motor OilAdvanced formula for cleaning and protectionBest for ProtectionCheck Price
Pennzoil Platinum Full Synthetic 5W-20 Motor OilUses gas-to-liquid PurePlus TechnologyBest OverallCheck Price

Let’s take a closer look at the specifics of these oils now.

Generac Full Synthetic Motor Oil 5W-20

Recommended By The Manufacturer:


  • High-quality synthetic base fortified
  • Includes advanced additives

Unique Features:

  • Performs exceptionally well in extreme temperatures. 
  • Helps extend its overall lifespan


  • Ensures maximum protection and longer engine life
  • Decrease engine noise 
  • Smoother operation


  • Higher price compared to similar oils

One standout feature of this motor oil is its high-quality synthetic base fortified with an advanced additive. This combination ensures maximum protection and longer engine life. 

This is exactly what you need to maintain the optimal performance of your generator.

You will appreciate its specific design to be used in Generac 22kW air-cooled generators. The proprietary 5W-20 synthetic oil formulation is spot on. You will notice a significant decrease in engine noise and smoother operation.

One of the major benefits I’ve observed is excellent protection against deposits and sludge. My generator’s engine stays clean and free from harmful build-up. 

Additionally, the Generac Full Synthetic Motor Oil 5W-20 performs exceptionally well in extreme temperatures. Not only does this motor oil protect my generator’s engine, but it also helps extend its overall lifespan.

If you are looking for the perfect oil for your generator, this should be the first option you should consider. 

Mobil 1 Extended Performance Full Synthetic Motor Oil 5W-20 

Best Budget-friendly:

Unique Features:

  • Has multiple certifications
  • Meets the highest industry standards for engine protection
  • 2x better protection and fuel economy. 
  • Provides great value for money


  • Provides optimal engine protection.
  • Reduces wear and tear.


  • Limited availability

When it comes to motor oil, Mobil 1 has established itself as one of the best and most trusted brands globally. Their Extended Performance Full Synthetic Motor Oil in the 5W-20 viscosity grade is a top contender in the market. 

After using it in my Generac 22kW generator, I understand why it consistently ranks among the best.

First and foremost, Mobil 1’s adherence to motor oil standards is commendable. The 5W-20 oil satisfies the highest class of SP according to the API standard. This standard is crucial in evaluating motor oil, and Mobil 1 exceeds expectations in this regard.

Mobil 1 Full Synthetic Oil is its 2x better protection capability. This means that you can rely on this oil to provide long-lasting lubrication and engine protection. This is particularly beneficial for generator owners who desire extended maintenance intervals.

As a fully synthetic oil, Mobil 1 offers superior performance and protection. The synthetic formulation ensures excellent lubrication across a wide range of temperatures and operating conditions. It maintains its viscosity even in extreme heat or cold. 

This provides optimal engine protection and reduces wear and tear.

Mobil 1 Full Synthetic Oil meets the ILSAC GF-6A specifications, further emphasizing its quality and performance. This specification ensures that the oil meets the highest industry standards for engine protection, fuel efficiency, and emissions control. 

Rest assured that your Generac 22kW generator’s engine will benefit from the advanced technology and protection.

The API Starburst certification is another testament to the Mobil 1 Extended Performance Full Synthetic Motor Oil’s excellence. This signifies that the oil meets or exceeds API performance requirements, giving customers confidence.

The Mobil 1 is so pocket friendly that you can also use it for other purposes, like using it in the Yamaha EF2000is portable inverter

Valvoline Advanced Full Synthetic SAE 5W-20 Motor Oil 

Best Protection:

Unique Features:

  • Provide 25% more protection against deposits
  • Incorporates anti-wear additives
  • Meets the API Service SP and ILSAC GF-6A standards
  • Advanced formula for cleaning and protection


  • Guaranteed protection 
  • Reduce friction and enhance heat resistance


  • Low fuel economy compared to others

As an American manufacturer with a strong presence in the lubricant industry, Valvoline is known for producing high-quality products. Their Advanced Full Synthetic motor oil is no exception. I had a chance of using this oil a while back.

In my experience, the Valvoline Advanced Full Synthetic SAE 5W-20 Motor Oil is a highly reliable and well-regarded option. The feature that I liked the most about this motor oil is its advanced formula. 

This formula includes extra detergents that provide 25% more protection against deposits compared to industry standards.

The Valvoline Advanced Full Synthetic Oil also incorporates anti-wear additives that effectively keep the engine intact. These additives reduce friction and enhance heat resistance. 

This ensures consistent performance and peace of mind, even during demanding usage or extreme operating conditions. 

In terms of certifications, Valvoline Motor Oil meets the API Service SP and ILSAC GF-6A standards. It also carries the API Starburst certification, further reinforcing its quality and reliability.

This oil is so great, it is considered one of the best oils for Champion generators.

Pennzoil Platinum Full Synthetic 5W-20 Motor Oil 

Best Overall:

Unique Features:

  • Uses gas-to-liquid PurePlus Technology
  • Helps protect engines from loss of powe
  • 15 years warranty
  • Formulated to provide faster low-temperature oil flow and protection in extreme heat


  • Improve the fuel economy 5 times more than other oils
  • Cleans your generator engine up to 45% better than industry standard oil


  • Costs more than double than other engine oils

This Pennzoil Platinum Oil is like a celebrity among the other engine oils. I have never had the fortune to use it myself, I have seen first-hand what it can do.

With their patented gas-to-liquid PurePlus Technology, Pennzoil offers a unique formulation made from natural gas. As a result, a high-quality full synthetic oil that tops the industry is made.

Its ability to provide better fuel economy is one of the standout properties of Pennzoil Platinum Oil. With regular use, this oil can improve the fuel economy 5 times more than other oils. 

This not only helps save money on fuel but also reduces environmental impact. Pennzoil Platinum keeps your generator engine up to 45% cleaner than the toughest industry standard oil. 

This is not just talking but is proved by the Sequence IIIH results. A cleaner engine will contribute to improved engine performance, reduced friction, and enhanced overall efficiency.

When it comes to wear protection, Pennzoil Platinum stands out from the competition. The Sequence IVA wear test using SAE 5W-20 oil provides better wear protection from friction compared to other leading synthetic oils. 

This ensures that your Generac generator’s engine is well-protected, even under demanding operating conditions.

One of the key advantages of choosing Pennzoil is its long-term warranty plan. They are the only company to offer a warranty or guarantee on the quality of their oil for 15 years. 

This engine oil is so good, it can be used on top-rated and high-power generators like the Pulsar 1200-watt generator.

Oil Buying Guide For Generac 22kw Generators

No matter what oil you decide to buy for your Generac generator, you must keep some things in mind. Let’s see what those are.

Type of Oil:

In selecting oil for your generator, the first thing to consider is the oil type. Generators usually require either synthetic or conventional oil. 

A conventional oil, also called mineral oil, is refined from crude oil through a refining process. It performs well under standard operating conditions and provides decent lubrication. 

Synthetic oil, on the other hand, is artificially engineered to improve performance and protection. It offers better viscosity stability, improved temperature resistance, and superior wear resistance. 

In spite of its higher price, synthetic oil is an excellent choice for demanding or extreme operating conditions.

Flow Rate:

Oil viscosity, also known as flow rate, is an essential characteristic to consider when selecting oil for a generator. It is usually indicated by a combination of letters and numbers, for example, 10W-30. 

Oil’s viscosity at low temperatures is represented by the first number, while its viscosity at high temperatures is represented by the second number. 

For Generac generators, it is recommended to choose an oil viscosity of 5W-20.

Choosing the right viscosity helps minimize wear and tear on engine components by ensuring proper lubrication during startup and continuous operation.


When choosing engine oil for your generator, it is crucial to consider API certification. That’s because it ensures that the oil meets all industry performance and quality standards. 

The API assigns different service categories, such as API SN, API SJ, or API CI-4 to oils based on their ability to meet specific requirements. For most generators, oils with API SN or higher ratings are recommended. 


Another vital aspect of choosing your generator oil is choosing a reputable brand that provides quality. Well-established brands usually produce high-quality oil that meets or exceeds industry standards. 

Choosing a trusted brand will ensure that you get a product that is reliable and performs consistently. Some popular brands known for their generator oils include Mobil 1, Pennzoil, Valvoline, and Castrol. 


Finally, you must understand the conditions under which your generator operates. A variety of factors can affect the oil’s performance, including the climate, ambient temperature, and the operating environment. 

If you live in a climate with extreme temperature fluctuations, you may need a generator oil with a wider viscosity range. If you intend to use your generator in dusty or humid conditions, you should choose an oil that offers enhanced protection against contaminants. 

Select an oil that will provide lubrication and protection for your generator based on its specific usage conditions.


With this, I conclude my review of the best oil for Generac 22kw generators. I tried to pick the oils that I personally found to be the best from my personal experience. Please feel free to add to my list if you think I have missed anything. 

If you have tried any of the oils, which one did you like the most? Do let me know in the comments.

Frequently Asked Questions (FAQs):

How many quarts of oil does a 22kw Generac generator take? 

The oil capacity for a Generac 22kw generator is approximately 1.7 quarts. However, you can also use 2 quarts of synthetic oil. But for confirmation, you should refer to the respective owner’s manual or contact Generac customer service for guidance on oil capacity.

Can you use 15w40 oil in a generator?

Yes, 15W40 oil can generally be used in a generator. But it is important to consider the type of engine and the temperature conditions. But still, for confirmation, you should refer to the specific owner’s manual. 

How much fuel does a 22kW generator use per hour? 

The fuel consumption of a 22kW generator can vary depending on the load and the type of fuel used. At 25% load, it can use approximately 1.1 gallons per hour, at 50% load it can burn around 2 gallons per hour, and at full load, it can consume between 3.6 gallons per hour.

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