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Best Oil for Generators 2020 – Reviews & Top Picks

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Oil suited for a generatorPortable gas generators are not simple machines. At the heart of the generator is the engine, with oil as its blood. But how do you know what oil to choose? The market is so large, and there’s so many different classifications. Maybe you are unsure of the difference between conventional oil and synthetic oil? We are here to help! In these reviews of the best oils for generators, we offer a resource for you to learn and compare.


The Winning Choices of 2020 Compared:

ModelPriceWeightEditor Rating
Delo 39086
small Delo 400 SAE 30
Best Overall

Check Price
Briggs & Stratton 100028
small Briggs & Stratton 30W Engine Oil - 48 Oz. 100028
Best Value

Check Price
AmazonBasics AM0D533Q
small AmazonBasics AM0D533Q
Premium Choice

Check Price
Honda 08207-10W30
small Honda 08207-10W30

Check Price
Briggs & Stratton 100074
small Briggs & Stratton 100074

Check Price

The 7 Best Oils for Generators:

1. Delo 39086 Motor Oil – Best Overall

Delo 400 SAE 30

A sign of a good product is versatility, and this oil sure has it. Trusted for portable gas generators, it’s also trusted for many other engine types, including cars and trucks. It’s easy to see why it’s recommended by mechanics. This oil will leave your engine running clean and give it a long life.

Due to the formula used by Delo, you won’t have to deal with oil gelling, viscosity increase, or wear and tear to your polish. This is an ideal oil for 4-stroke engines and is not recommended to be used with 2-stroke engines. It is not uncommon for this to be the only oil that people use across all their equipment. Sometimes the packaging shows up a bit disheveled, but the product is still perfectly fine.

  • Versatile
  • Keeps filter clean
  • Leads to long engine life
  • Poor packaging

2. Briggs & Stratton Engine Oil – Best Value

Briggs & Stratton 30W Engine Oil - 48 Oz. 100028

This oil from Briggs & Stratton has a couple things going for it. First, it’s great for use in most four-cycle engines. Secondly, it comes in a huge jug! This oil is especially good for portable gas generators, but you need to check the levels often. You’ll also want to read the user manual to see what grade of oil you will be using. Because of its versatility and bulk size, it is easy to see why we think that this oil from Briggs & Stratton is the best portable gas generator oil for the money.

  • Can be used on a variety of engines
  • Great for portable gas generators
  • Have to check oil levels often

3. AmazonBasics Synthetic Motor Oil – Premium Choice

AmazonBasics AM0D533Q

Made to resist viscosity and reject thermal breakdown, you can run a portable gas generator with confidence with this oil from AmazonBasics. This is a full synthetic motor oil, meaning that it can be used in all temperatures, and it is specifically formulated for long drain intervals. It is also designed for volatility burn off, which minimizes engine deposits and decreases exhaust emissions. This oil is meant to help elongate your gas mileage and prevent you from low speed ignition.

While this oil is wonderful for portable gas generators, you may want to think twice about using it in your car, or at least check to see if it is certified by your car manufacturer.

  • Resists viscosity
  • Fully synthetic
  • Decreases exhaust emissions
  • Not to be used for several car types

4. Honda 08207-10 Motor Oil

Honda 08207-10W30

This oil for Honda is wonderful, but it has one caveat: You must use it with Honda equipment. That means you can use it for your car, mower, or even portable gas generator. While it is versatile within the products offered by Honda, that’s all it’s really good for. It’s also a bit pricey, so we can only recommend this product if you have Hondas for all your power equipment.

  • Top-of-the-line oil
  • To be used in all power equipment
  • Only to be used with Hondas

5. Briggs & Stratton Small Engine Motor Oil

Briggs & Stratton 100074

Briggs & Stratton reappears on this list with an oil made for small engine power equipment. This oil is specifically made to be used with portable gas generators and other power equipment that have air-cooled four-cycle engines. Briggs and Stratton burns off quicker than some of its competitors, so you will want to check your oil levels often, but it burns clean and effectively. If you decide to go with the synthetic option, it will not change the intervals at which you change your oil. A complaint with this product is that for something so specific, it is a bit expensive.

  • Burns clean
  • To be used specifically with air-cooled four-cycle engines
  • Price

6. Cummins 3265336 Onan SAE Oil

Cummins 3265336

Cummins has made an oil specifically to reduce consumption and engine wear. Factory tested, this oil from Cummins was designed to be used with the Onan gas generator. It does burn quick, however, and will need to be changed frequently. You could use other oils with the Onan, but for full functionality, we recommend going through the slight pain of changing your oil regularly with the Cummins. You will also need to run your Onan quite often, as you can encounter moisture buildup if you don’t. This oil is also pretty expensive.

  • To be used with Onan gas generator
  • Heavy synthetic oil
  • Needs changed frequently
  • Price

7. Generac 0J5140 Synthetic Motor Oil

Generac 0J5140 Full Synthetic Motor Oil

This oil from Generac is generic but it gets the job done! Nothing too special, which is why it is number 7 on this list, though we still thought it was good enough to mention. This oil is formulated to protect against the formation of sludge and varnish deposits, and it is fortified against viscosity breakdown. The bummer is the price. You will also probably need to buy more than one bottle, as most portable gas generators require more than what you get out of a single bottle of this.

  • All-around good product
  • Protects against sludge, viscosity, deposits
  • Price
  • Size

Buyers Guide

Most of the time, when it comes to oil, loyalty comes into play, While no two items are quite the same, with oil, there is a good deal of similarity. Of course, there are instances where certain companies make oil specifically for their products (see: Honda, Cummins). What other factors should you think about when buying oil? Let’s take a look.

Conventional or synthetic?

This comes down to how much you want to pay. As a rule of thumb, conventional oil costs about one-third the price of synthetic oil. So, why should you opt for synthetic? Synthetic oil typically lasts much longer and has a better threshold for extreme temperatures. With conventional oil, you will buy one rated for thickness and temperature based on the weather when you are using it.


Will you be using this oil just for your portable gas-powered generator or for other items as well? When it comes to versatility, that’s where we see the biggest difference in oils. Some can be used for all motors, some for small motors, others for specific types of motors, and still others are specific to the manufacturer.


Certain oils burn cleaner than others. You’ll want to look into this if you are worried about your carbon footprint.

Length of time.

As we discussed with conventional vs. synthetic oils, different oils last for different amounts of time. Why buy an oil that doesn’t last that long? There could be many reasons, from price to cleanliness.


We know that the market for oil is huge, and finding one that is right for your portable gas-powered generator isn’t easy. We hope that you use these reviews as a reference not only now but also in the future.

Whether you choose the offering from Delo(our top pick) or decided to save a bit of money and go with a big jug of Briggs & Stratton, we are happy to help you on your journey.

Featured Image Credit By: AmazonBasics Full Synthetic Motor Oil, amazon

About the Author Adam Harris

Hi there! My name is Adam and I write for HealthyHandyman. I have a great passion for writing about everything related to tools, home improvement, and DIY. In my spare time, I'm either fishing, playing the guitar, or spending quality time with my beloved wife. You'll also often find me in my workshop working on some new project!