Best oil for generators

1. Honda 08207-10W30 Motor Oil
2. Briggs & Stratton 30W Engine Oil – 48 Oz. 100028
3. Generac Full Synthetic Motor Oil 5W-30 SN Quart Bottle Part# 0J5140 (qt)
4. Cummins 3265336 Onan SAE 15W-40 Oil – 1 Quart
5. Briggs & Stratton SAE 5W-30 Synthetic Small Engine Motor Oil
6. Husqvarna XP 2 Stroke Oil 2.6 oz. Bottle 6-Pack

According to toolspost expert team, Shell Rotella T6 Full Synthetic Oil is the best oil for generators in 2019.

It is often overlooked that the most important moving part of any engine is its oil. Engines do not function without oil. When it comes to generators, it might be absolutely necessary to have the right oil and maintain it properly.

Generators are by definition important equipment; if you need one to pump heat, light and water, you really want to make sure your oil is up to date. When you need best synthetic oil for Toyota Corolla, read our review about this.

6 Best Oils for Generators in 2019 - Reviews and Buying Guide

6 Best Oils for Generators in 2019 – Review 2019

1. Honda 08207-10W30 Motor Oil

2. Briggs & Stratton 30W Engine Oil – 48 Oz. 100028

3. Generac Full Synthetic Motor Oil 5W-30 SN Quart Bottle Part# 0J5140 (qt)

4. Cummins 3265336 Onan SAE 15W-40 Oil – 1 Quart

5. Briggs & Stratton SAE 5W-30 Synthetic Small Engine Motor Oil

6. Husqvarna XP 2 Stroke Oil 2.6 oz. Bottle 6-Pack

Top rated oils for generators

Different types of engines require different types of oil, and generators are special machines. If they are used with the right oil, they should never let you down.

Synthetic oil for generators

Do you need a new oil for your generator but have no idea how to choose it? Then take a detailed look at our Buyer’s Guide. In addition to the tips and features you should be looking for, you will also learn more about the best and most reliable oil brands we recommend.

Our top picks of the best oils for generators 2019

1. Honda 08207-10W30 Motor Oil

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This high-quality engine oil is sold by Honda especially for use with its own products. It has Honda as original equipment manufacturer (OEM) on the bottle and is designed for Honda four-stroke engines used by generators, lawnmowers, scooters, go-karts and mopeds.

Therefore, it is strongly recommended to use this oil only if you have a Honda generator. It does its job when starting up, which is extremely important for two-stroke engines.

This oil will make your generator engine more efficient even if you use it as a refill solution for oil of a different specification. However, as far as the price is concerned, it is on the high side.


  • Well-known brand
  • Meets / exceeds SN API
  • Quick lubrication


  • A little pricey

2. Briggs & Stratton 30W Engine Oil – 48 Oz. 100028

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From Briggs and Stratton comes the excellent engine oil that is perfect for generators. B & S are one of the best-known engine manufacturers in the USA and market oils that make their engines work better and last longer.

Fortunately for us this means that they also work excellently with other engines. This special mixed engine oil has some big advantages for generator engines.

It is a detergent oil, i.e. it keeps your engine clean by preventing the accumulation of waste products. Its formulation is designed to work best at high temperatures, such as those found in generator engines. It is also very inexpensive and comes in a convenient bottle.


  • Good for warmer temperatures
  • Warranty certified


  • A little expensive

3. Generac Full Synthetic Motor Oil 5W-30 SN Quart Bottle Part# 0J5140 (qt)

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Generac Power Systems is a leader in generator technology and this product is part of this process.

This is a synthetic oil that is becoming increasingly popular with users of high-temperature motors in general and generators in particular.

Traditional engine oil, refined from crude oil, changes over time and is exposed to heat. Basically, it gets thicker.
For a lubricating oil this of course poses massive problems. Thicker oil cannot move around the engine as intended, and your engine jams. If you have ever experienced this, you will appreciate the value of synthetic engine oil. This oil is fully synthetic and very valuable.


  • Created for generators
  • Exceeds highest API class
  • Protects against deposits


  • Too expensive

4. Cummins 3265336 Onan SAE 15W-40 Oil – 1 Quart

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Cummins generators are highly regarded throughout the industry and their Onan brand is part of their reason to have such a good reputation. This one-quarter engine oil bottle has everything you would expect from such industry leaders.

Cummins use this oil for their own generator engines of a certain type, the type you and I use. The oil is tested in their own factories to make sure the engines work optimally.

It is designed for diesel engines, but also works excellently in gas-powered generators. It is designed to increase engine efficiency by resisting the viscosity caused by very hot engines.


  • Provides maximum protection for engines
  • Reduces consumption and engine wear
  • Factory tested oil


  • None

5. Briggs & Stratton SAE 5W-30 Synthetic Small Engine Motor Oil

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This excellent synthetic oil comes from Briggs and Stratton. It is designed for use in small four-stroke engines such as those found in some generators.

In addition to overcoming the viscosity problem of conventional engine oils, this is also a detergent oil that keeps the functional parts of your engine trouble-free. This is ideal for fuel efficiency and longer engine life.

Synthetic oil is also known for its ability to start working immediately after heating. Again, since the molecular structure does not need to heat up to lubricate properly, you can trust this oil in winter.


  • For Use In All Air Cooled 4-cycle Engines
    Use of synthetic oil does not alter required oil change intervals


  • Different oil types can work best at certain temperatures. Learn which one to choose for your climate.

6. Husqvarna XP 2 Stroke Oil 2.6 oz. Bottle 6-Pack

Buy Husqvarna XP 2 Stroke Oil 2.6 oz. Bottle 6-Pack

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Although the vast majority of generators used 4-stroke engines, there are some machines with “old-school” two-stroke engines. If you own one and need a new oil, choose Husqvarna XP+.

Husqvarna is a well-known manufacturer of small machines that use 2-stroke engines, so they have a lot of experience in formulating the right oil. This semi-synthetic oil is JASO-FD certified to meet the latest standards and requirements.

In addition, Husqvarna XP+ includes a fuel stabilizer and ensures low operating temperatures, resulting in better engine protection and less smoke. Fortunately, this oil is still on the affordable side.


  • Excellent for 2-cycle engines
  • Low operating temperatures
  • Low smoke formula


  • None

Quick Tips to Buy the Best Oil for Generators


As always, the first step in our Buying Guide is to take a look at the user manual or instruction manual you received with your generator. You will find any information you will ever need inside, so do not throw it away.

From your own experience, you will usually find information about the engine oil you need in the Maintenance section of your manual.


The most important feature to consider when selecting the engine oil for your generator is its viscosity. As mentioned above, you will find the recommended type in the Owner´s Guide or Manual.
In most cases you will need a SAE 10W-30.

The SAE refers to the rating system developed by the Society of Automotive Engineers. The rest of the code refers to the viscosity oil´s at different temperatures.

The first number in the code, in this case 10W, means how well this oil can be extracted at cold temperatures. The W refers to the word winter (not the weight). The second number in the code indicates how well the oil can be pumped when heated to 212 degrees Fahrenheit (100 degrees Celsius) or higher.

In addition, you should choose a high quality detergent oil with the service classifications SJ, SL, SM or SN of the American Petroleum Institute (API).

However, always check the correct type of oil in your instruction manual and do not rely solely on our recommendations. It may vary from one generator type to another. Filling in an oil other than the recommended one may cause premature wear of individual engine parts.


Another thing to consider when choosing the best oil for your generator is the temperature of the environment you will be using it. In fact, this has been highlighted in every single user manual we have seen.

If you will be using your generator in a very cold environment that only allows very low starting temperatures, a 5W-30 may be a better option for you. However, you must be aware that this oil is associated with increased engine oil consumption at higher operating temperatures, so check its level before each use.


Another thing you should consider before deciding what oil is good for your generator is to know what type of engine it is using. In our experience, there are only a small number of generators with a 2-stroke engine and a large majority of generators with a 4-stroke engine.

Each type requires a different type of engine oil.

While in a 4-stroke engine you use oil and fuel separately, in a 2-stroke engine you can either mix fuel and engine oil in a recommended ratio yourself or you can buy a premixed solution.


Finally yet importantly, you should never try to save engine oil for your generator. Favoring a lower price over a high quality product can lead to major concerns later on.

Rather, you should invest a little more in reliable brands, such as:

  • Honda
  • Onan
  • Briggs & Stratton
  • Mussel Rotella
  • Engine 1
  • Generic
  • Craftsman

The purchase of the right generator oil is crucial for the functioning of your engine. As we have seen, the generator manufacturers themselves produce oils that give their own products the best performance and longest life.

While these are some of the biggest names in the generator market, engine oil sold for use in these and other engines of similar size and speed may be derived from brand names more commonly associated with the automotive industry.

It is worth being careful. Choosing the wrong oil could be expensive and cost you more than money.

Here are some things to consider when choosing the engine oil for your generator:

Do you know your generator?

There is a wide range of power generators on the market, which makes the choice of oil more difficult than before. Largely, portable generators have been manufactured by certain companies to work with fairly normal oils;

Therefore, if yours breaks down at a campsite, you can probably borrow some from another friendly camper.
Today, generators are more readily available in manufacturing forms that require specific maintenance, including generator oil. Manufacturers will always recommend their own brand of engine oil;

However, it is still the case that other brands can function well. While the choice is greater, you can find a brand of oil on the market that actually has a better value.

Many people who rely on generators have the same for years and years. Reliability is by far the most important factor in usage.

This applies to the oil that keeps them running; and as the saying goes, if it is not broken, do not fix it. In today’s market this may not be such good advice. Do some research.

Real or synthetic?

This is a question that is often rightly asked when it comes to oil for generators. While the users of other engines may not have a choice for different applications, the increasing demand for synthetic lubricating oil often comes from the users of such small engines.

The main reason for this is the temperature these engines reach. Two-stroke engines rely on high temperatures to work efficiently, and traditionally generators have used them.

As we have seen in some of our reviews, synthetic engine oil is highly recommended for use in these engines, as it does not suffer from the problem of increased viscosity.

Synthetic oil is otherwise a consistent product; its price does not depend on that of a barrel of crude oil. Although it can be more expensive to bottle, its properties mean that it lasts longer than conventional engine oil. In the long run, this can save you money.

Of course, more oil that is powerful means a more powerful generator. This means less fuel, which is a consideration. Over time, synthetic oil will maintain your engine very well. Besides avoiding stalls and traffic jams, this can mean that you never have to buy a new generator.

It may not be at the top of the list, but there are also environmental aspects to burning fossil fuels. Apart from everything else, it will run out one day.

Concluding remarks

As the technology advances, we will have more choices. This applies to generator oil as well as everything else mechanical. Just to drive the point home, engine oil is a part of your engine.

As technology advances, synthetic oils become cheaper and can compete better with the old type.

For such a cheap product, it is worth thinking about what you are actually buying. For many people, engine oil is an afterthought; think about fuel, etc., until their generator stops working.

We hope that our guide to the best generator oils will help you make the right choice.

6 Best Oils for Generators in 2019 – Reviews and Buying Guide Video

6 Best Oils for Generators in 2019 – Reviews and Buying Guide
5 (100%) 4 votes
David Muench (Carnes Mechanical)

David Muench (Carnes Mechanical)

Hey, I’m David. I’ve worked in a cars store for 6 years. I write reviews and guides, helping people to choose the most suitable technicals and best product for them. I’m happy to finally share my knowledge of the industry here, on CarnesMechanical.

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