Most manufacturers recommend that you use conventional motor oil in their generators. Some manufacturers may even void the warranty if you do not use the recommended oil.
So, can you use synthetic oil in a generator? The truth is that synthetic oil is likely to provide a better option compared to conventional oil for a generator.
Synthetic oil breaks down at a slower rate and contains fewer impurities, decreasing the buildup of sludge and extending the time between oil changes.
Yet, before you buy synthetic oil for your generator, you should ensure that you select the right type. Here is what you should know about synthetic oil for generators.
Conventional vs. Synthetic Oil for Generators: What’s the Difference?
Synthetic oil was designed to address some of the limitations of conventional motor oil. Oil manufacturers make conventional oil using petroleum, which is naturally thick at low temperatures and thin at high temperatures.
Manufacturers use additives to adjust the thickness of the oil. For example, with conventional 5W-30 oil, the thickness of the oil is reduced for lower temperatures and thickened for higher temperatures for better performance.
The thickness of the oil is often referred to as its viscosity.
5W-30 is a multi-grade oil. The oil has a viscosity of 5 in cold temperatures and 30 in hot temperatures.
Increasing the viscosity of the oil makes it thinner and flow easier, allowing it to lubricate components. If the oil becomes too thin, it cannot properly do its job.
Yet, if the oil becomes too thick, the generator may not start as easily or run as efficiently. The additives used to adjust the thickness of the oil gradually break down, creating the sludge that you may see when changing oil.
As the additives in the oil break down, the thickness of the oil returns to normal. The oil becomes less effective at low temperatures and high temperatures.
Synthetic oil is made to maintain its viscosity. Unlike conventional oil, synthetic oil does not degrade.
However, contaminants can still reach the inside of the engine and slightly increase the thickness of the oil.
Why Use Synthetic Oil in a Generator?
Full synthetic oils are made using the highest-quality base oils and altered using additives. Producing synthetic oil also allows manufacturers to remove impurities that are commonly found in standard crude oil.
Synthetic oils are carefully formulated for optimal performance, which leads to several distinct benefits for your generator:
- Superior viscosity at low and high temperatures
- Increased protection against wear and tear
- A reduced buildup of sludge and deposits
Synthetic oil offers superior viscosity at both low and high temperatures. It is less likely to thicken at low temperatures or become too thin at high temperatures, which increases the protection of the engine.
Oil is needed to protect the engine components and extend the life of your generator. If the oil is too thin, the lack of protection from the friction of moving parts causes increased wear and tear.
Thick oil increases wear and tear by forcing the components to work harder to push through the sludge and deposits. Full synthetic oil contains fewer impurities, which limits the buildup of deposits.
Synthetic oil also tends to last longer compared to conventional oil. You may not need to change your oil as frequently, as synthetic oil retains its viscosity better and produces less sludge.
How to Choose the Right Oil for Your Generator
Pay attention to the following details when choosing oil for your generator:
- The manufacturer’s recommendations
- The temperature range in your region
- The viscosity of the motor oil
You should first check the instruction manual that came with your generator to find the manufacturer’s recommendations. Some generators may even come with a small bottle of oil.
Recommendations vary from one manufacturer to the next. For example, Briggs & Stratton recommends that you use conventional or synthetic oil while Yamaha recommends that you only use conventional motor oil.
Not using the recommended oil may void the manufacturer’s warranty. A common practice is to stick with the manufacturer’s recommendation when adding oil for the first time.
When it comes time for an oil change, you can switch to the oil of your choice. You also need to consider the temperature range in your region during the periods when you plan on using a generator.
Colder temperatures typically decrease the viscosity of the oil, making it thicker and forcing the oil pump to work harder to push the oil through the engine block. High temperatures increase the viscosity of the oil, allowing it to flow easier, but limiting protection.
How to Choose the Right Viscosity of Oil for a Generator
Manufacturers list the viscosity of the oil at low and high temperatures. For example, 5W-30 is a common type of motor oil.
The “W” stands for winter. The number before the “W” refers to the viscosity of the oil in cold weather.
The second number refers to the viscosity of the oil at high temperatures. A low number means that the oil is less viscous (thinner) while a higher number means that the oil is more viscous (thicker).
The viscosity typically ranges from 5 to 40 in increments of 5. A 5W oil remains effective at temperatures as low as -22 degrees Fahrenheit (-30 degrees Celsius).
A 10W oil remains stable down to temperatures of -13 degrees Fahrenheit (-25 degrees Celsius). If temperatures frequently drop below freezing when you use your generator, a 5W oil may work better.
The viscosity at high temperatures is also important.
An oil with a viscosity of 30 is stable at temperatures up to 86 degrees Fahrenheit (30 degrees Celsius). An oil with a viscosity of 40 is stable at temperatures up to 104 degrees Fahrenheit (40 degrees Celsius).
If you live in a region with cold winters, you will likely use 5W-30 oil. For those in warm regions with mild winters, a 10W-40 oil may work better.
How Long Will Synthetic Oil Last in a Generator?
With conventional motor oil, most generators require an oil change after the first 25 hours of use. After the first oil change, manufacturers typically recommend changing the oil every 50 to 60 hours.
Synthetic oil often lasts longer compared to conventional oil, as it contains fewer impurities and breaks down more slowly. It offers extended protection, which may allow you to change the oil after every 100 hours of use.
You should also check the oil before operating it. If you run the generator for long periods, you should also check the oil after every 8 to 12 hours of use.
Final Thoughts
You can typically use synthetic oil in almost any generator without any issues. Compared to conventional motor oil, synthetic oil tends to offer longer protection, as it degrades at a slower rate.
Yet, you should also follow the manufacturer’s recommendations, especially when adding oil for the first time. Using conventional oil may initially help lubricate the engine components a little better but increases the risk of buildup when used long-term.
You should also pay attention to the viscosity of the oil that you choose. Multi-grade oils include two viscosity ratings, a winter rating and a hot weather rating.
5W-30 oil is suitable for regions with cold winters while 10W-40 oil is typically used in areas with hot summer and mild winters.
I have a bachelor’s degree in construction engineering. When I’m not constructing or remodeling X-Ray Rooms, Cardiovascular Labs, and Pharmacies…I’m at home with my wife, two daughters and a dog. Outside of family, I love grilling and barbequing on my Big Green Egg and working on projects around the house.