Can You Use Synthetic Oil In a Honda Generator?

There is no question that Honda is among the most reliable generator brands on the market. But, the efficiency of a generator does not only depend on the generator itself. Part of what makes most Honda generator models work is the oil. Choosing the best oil for your generator increases its reliability and durability.

Generally, Honda generators run well on synthetic oil. It’s best to run most brand new generators on conventional oil for the first 15 hours, but after that, synthetic is a great and affordable option. It’s good to know that switching between synthetic and traditional oil does not harm your engine.

Here, we look at the oil you can use in your generator for effective performance. 

Is Synthetic or Regular Oil Better for a Generator?

Are you seeking the best oil for your generator? The best oils for your generator are the same synthetic oils you use for the car. Any quality synthetic 5W-30 oil is perfect for your generator.

The oil you use in your generator depends on how you use it and the type of generator you have. You should therefore go through the manual to know the oil type that is compatible with the generator. 

In most cases, the type of oil to use depends on the engine type and some additional parameters. 

We recommend that you select the oil you use based on viscosity. There are other factors to consider, including the intensity of usage, the wearing of your generator, outdoor temperature, among others. 

What Kind of Oil is Best for a Honda Generator?

If you have a Honda generator, you need to use 10W-30 motor oil. Determining the exact type of oil to employ in your generator will mainly depend on viscosity or its thickness. 

For instance, in the case of 10W-30, the number 10 represents the thickness of oil at cold temperatures. ‘W’ refers to the winter season when the temperature is cold. The last number, ’30’, represents the viscosity of the product when it’s warmer. 

The 10W-30 oil will function in almost any condition your generator operates in regardless of the temperature. This product is among the most common oil types, and you can purchase it anywhere. 

However, if you decide on using a different product in your Honda generator, ensure that it’s a high-quality oil. Ensure the oil can offer maximum efficiency for a long time. 

What Oil Should You Use In Your Honda Generator?

If you’re leaning towards using synthetic oil for your generator, below are the top synthetic generator oils to consider:

Generator OilProsCons
Amazon Basics Dexos 1-Gen2Limits low-speed pre-ignition, extended drain intervals, and is Dexos 1-Gen2 compliant.It isn’t easy to know how much is remaining in the bottle.
Briggs & Stratton 30W OilExcellent lubricant, viscosity, and comes in a comfortable-to-use bottleEven though the bottle has a safety seal, it can still leak.
Briggs & Stratton 2-Cycle OilIt’s a very affordable oil, allows a mix of 50:1, and is great for many two-cycle generator engines.The dispenser is a little awkward to use.
Generac 5W-30Specifically designed for generators, good viscosity, wide temperature range, and discourages sludge deposits.This oil has a good reputation and sales numbers in comparison to other products.
Mobil 1 5W-30Name brand, promotes good run time, wide temperature range but especially good for cold weather.Not the best oil for a brand new generator because it is synthetic.
Shell Rotella T5Triple Protection technology, good for diesel engines, has good performance and is affordable.Can have problems with the container leaking.

1. Amazon Basics Dexos 1-Gen2 Full Synthetic Oil

If you’re seeking the best portable generator oil, then look no further than the Amazon basics products. AmazonBasics is a branch of the popular Amazon company and is reputable for delivering office and basic home tools. The products delivered by the company include charging cables, electronics, batteries, home gym equipment, and video gaming. 

The product is designed to protect your generator engine even in the worst of weather conditions. There is no worry about the climate or weather of the area you intend to use the generator. 

Even though the product is shipped and retailed by AmazonBasics, Warren oil is the manufacturer. It’s an off-brand product that functions efficiently as the best option on the market. If you buy this oil, you’re sure to get some pretty impressive performance out of it. 

The product guarantees a longer drain interval on top of a top-class blend of engine oils. It offers greater protection against friction and is perfect for enhancing fuel economy. 

If you use the AmazonBasics products, expect less maintenance for your generator. Your generator will also get guaranteed durability. 

The oil is formulated to eliminate low-speed pre-ignition. It also surpasses the GM Dexos1-Gen2 requirements. It meets or exceeds the stipulations of SN, API, SL, and SN PLUS.

If you’re after a high-quality oil product for your machine at an affordable cost, this is the perfect product for you. 

2. Briggs & Stratton 30W Oil

The Briggs & Stratton 30W oil is the perfect choice for 4-cycle engines. The oil is manufactured by Briggs & Stratton, with over 110 years of experience producing quality engine oil. 

At the moment, the company is reputable globally for offering superior quality products. The brand acquired the backing of one of the biggest service networks in the oil industry. 

Apart from just manufacturing oil, Briggs & Stratton is also reputable for making small engines and marketing pressure washers. It’s also a top manufacturer of lawn care products and power generation machines. 

Briggs & Stratton has invested a lot of resources in innovation when it comes to oil production, thus the reason for increased customer satisfaction and constant improvement of products. The firm dedicates itself to solving customer needs and even strives to develop a diversified enterprise.

Briggs & Stratton 30W has gained the approval of many top engineers in the industry. They specifically designed it to deal with the hefty requirements of a 4-cycle engine. The API has classified this product as SJ/CD. 

While you employ this oil in your generator engine, we recommend that you check it regularly. An air-cooled engine will burn about 1-ounce of oil per cylinder in 1-hour. 

When refilling oil, ensure you do so up to the dipstick mark. Over refilling can cause different problems, including a reduced engine lifespan. 

This oil is ideal for warmer temperatures and is suited for small to medium generators due to it being an SAE 30 variant. 

3. Briggs & Stratton 2-Cycle Oil

Here is another top model that is the best product with a fuel stabilizer. However, this model is perfect for two-cycle engines. The model has grown into one of the most trusted products globally, especially for generators. 

The oil is designed to improve the working temperature of generator engines. It offers better performance compared to a variety of oils on the market. It can be attributed to it having a semi-synthetic formula. 

The benefit of this oil is that you can use it with a variety of generator models. If you apply, you’ll notice a reduction in the frequency of oil maintenance. It’ll also guard against plug fouling. 

Briggs & Stratton 2-cycle oil can blend with several fuel types. It’ll stabilize fuel, thus enhancing the engine’s longevity. If you employ this oil, you’re likely to note an increase in the stability and performance of your generator.

4. Generac 5W-30

The Generac 5-30 oil is the best-proven product for a wide temperature range. Generac has been in operation since 1959 and, since then, has acquired the reputation of producing quality products and services. Currently, Generac tops the list of domestic backup generator manufacturers. 

Apart from producing oil, Generac is also known for manufacturing industrial, commercial, and residential generators. It also ranks among the top manufacturers of manual and fully automated transfer switches. 

Generac 5-30 is a synthesized oil that has acquired widespread application among owners of high-temperature generators. They’re better in such situations than conventional oil, which changes over time and becomes thin when exposed to high temperatures. 

Conventional oil also becomes thicker under cold temperatures. As we all know, thicker oil doesn’t move effectively around the engine and might lead to jamming in the engine. To avoid such challenges, you better stick to the Generac 5-30 synthetic oil.

With the Generac 5-30 oil, your generator will attain uninterrupted results even with hail or rain. The product also prevents the deposition and formation of sludge deposits and varnish. 

The product is fortified with an effective additive to shield your generator against breakdown due to viscosity. We, therefore, recommend this oil for any homeowner who uses their generator at different temperatures, including cold winter and hot summer. The results that the oil offers won’t disappoint you. 

5. Mobil 1 5W-30

The Mobil 1 5W-30 product is the official oil of NASCAR. If you buy this product, you’ll be assured of its functionality even though some details require clearance. 

If you use your portable generator regularly, then a 5-quart bottle is enough. The products will protect your generator in both low and high temperatures. It’s also great for long runs. 

The composition of this oil helps to prevent the formation of sludges and deposits on the engine surface. However, since the oil is synthetic, we don’t recommend using it to start your generator. You can use regular natural oil for at least 15-hours. 

The oil will offer the best results, especially if you maintain it at above -40 degrees Fahrenheit. It’s, therefore, the perfect solution if you want a product for cold weather and small generators.

6. Shell Rotella T5

Shell is a reputable company known for manufacturing high-quality oil and fuel. Rotella is, therefore, a robust and durable oil from Shell performing at least 37% better than the maximum wear requirements set by API CK-4 tests. 

The oil is designed with a Triple Protection technology that helps to minimize friction in the engine. There is also an added protection against oil breakdown. The oil is perfect for 4cc generator engines. 

Shell Rotella T5 is formulated from a synthetic blend of advanced additives and synthetic base oils. The blending is relevant especially for diesel engines to counter any resistance in increased heat and stress. 

The product is also available at an affordable cost compared to other products on the market. 

Considerations When Selecting Generator Oil

We recommend that you consider the below factors before settling on a suitable oil for your generator

Read Your Generator’s Manual

The best approach to determine the type of oil for your generator is by reading the manual. Most manuals specify the oil you must use in your generator and provide information on soil type, season, and viscosity. 

Always buy the oil that meets the critical parameters.

Determine the Type of Engine

The engine type is critical information that you can usually find in the user’s manual. Here, the most important thing is the engine strokes. It matters whether the generator is a 2-stroke or 4-stroke engine. 

With a 4-stroke engine, you can either use SAE 10W-30 or SAE 5W-30 synthetic oils. 

Operating Temperature

When do you think you are required to use your generator? Will you just use it as a backup when the power goes off? 

If you’re going to employ it for some purpose, you should understand the conditions it’ll operate in. For instance, if you use it for winter tourism, you’ll need an oil meant for cold temperatures.

The 5W-30 oil is perfect for temperatures ranging from 100 degrees Fahrenheit down to -20 degrees Fahrenheit. If the operating temperature is below that, you should go for synthetic oils instead of conventional oils. The formula is intended for extreme temperatures. 

If your generator is operating in hotter weather, you should go for 10W-30 oils. Such products function ineffectively in cold temperatures by being less productive and getting thicker. They might show better results in hotter environments. 

Since a generator produces its heat while functioning, the 10W-30 oil is better in most cases. 

Check the Oil Viscosity

Viscosity refers to how smoothly oil flows at a certain temperature. If the oil is thicker, its viscosity is higher. A higher viscosity requires a higher temperature for the oil to function effectively. 

During winter, a low viscosity oil will function properly, while a higher viscosity one will fail. It doesn’t mean that you should always select an oil with a low viscosity. Thicker oils operate better at high temperatures. 

The value defines the oil’s viscosity at 100 degrees celsius before ‘W.’ For instance, 5W-30 oil has a lower viscosity than 10W-30 oil. The 5W will therefore function effectively in the cold while the 10W performs well in the heat. 

Stick to a Reliable Brand

A brand’s reputation is something that takes years of quality selling to achieve. For effective performance, always go for the tried and tested oils.

What Happens If You Put Synthetic Oil In a Non-Synthetic Engine?

Switching between non-synthetic and synthetic oils won’t cause any damages to your generator engine. In fact, synthetic blends are mixtures of conventional and synthetic oil. 

Mixing Oil

Mixing oil or switching between synthetic and non-synthetic oil is recommended by professionals. Since the oils are compatible, it’s unlikely that something bad might happen. 

Most oils are a blend of synthetic and natural oils. It means that if you find yourself low on oil, you can add a quart of synthetic oil to your non-synthetic engine. 

Possible Negative Effects

Even though you can mix synthetic and conventional oil, it isn’t something that you should do regularly. The mixture might destabilize the oil, and the additives in the products interact. It might therefore affect the oil property. 

Mixing the two oils makes it easier to lose the advantages presented by an expensive synthetic oil. Adding synthetic oil to your conventional oil might mean changing the oil sooner than you would have expected. 

A high-performance generator engine won’t allow expensive additives to function the way they’re supposed to. Even though it might not damage the generator engine, it might affect its efficiency.

Difference Between Synthetic & Regular Oil

Even though both synthetic and conventional oils come from petroleum, they’re different products. Non-synthetic or conventional products are refined from crude oil. The oil circulates in the generator engine to prevent wear and tear and keep it cool. 

It also seals the engine, keeps the surface clean, and prevents corrosion. Synthetic oil performs similar functions but can withstand higher pressures and temperatures. 

Like conventional oil, synthetic oil is also refined but purified and distilled with fewer impurities and smaller molecules. Synthetic oil is also developed with additives that help keep the engine clean and protect it from possible damages. 

The significant difference between the two is the temperature at which they undergo thermal degradation. For high-performance generators, conventional oil is more likely to form sludge and pick up deposits. 

Generators that run hot function well with synthetic oil. When it comes to cost, synthetic oil costs more initially but is more durable between oil changes


As we have seen, you can comfortably use synthetic oil in your Honda generator. Synthetic oil offers better protection than conventional oil. 

However, if you have a new Honda generator, you should operate it with conventional oil first. It’s allowed to switch between conventional and synthetic oil since it won’t damage your generator engine. 

For effective performance, you can select from any of the oils we have recommended above. However, before buying an oil product, consider different factors such as the brand, viscosity, operating temperature, and engine type. 


Hubert Miles

I've been conducting home inspections since 2002. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and an FHA 203k Consultant. I started to help people better understand whole-house and portable generators.

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