Skip to Content

How Often to Change Generac Generator Oil (Full Guide)

In this article, I show you how often you should change the oil in your Generac generator.
Also, I take into account various factors such as usage, type of oil, and more.

As a generator owner, you need to understand the importance of generator maintenance, especially when it comes to oil change. 

In this article, I focus on one of the most popular brands of generators, Generac.
Moreover, I discuss how often you should change the oil in your Generac generator.

Owning a Generac generator can be a lifesaver during power outages, providing you with a reliable source of backup power. 

To ensure that your generator continues to perform at its best, proper and routine maintenance is essential.
Ultimately, one critical aspect of maintenance is changing your generator’s oil.

How Often to Change Generac Generator Oil

As a general rule, standby generators require an oil change every 200 hours.
Portable generators require an oil change after every 100 hours of use.

The recommended oil change intervals for your Generac generator are outlined in the owner’s manual. 

This manual is your go-to resource for understanding the manufacturer’s guidelines for maintaining your new generator. 

Generac Generator Maintenance Kits

As the name implies, Generac generator maintenance kits contain sets of replacement parts.
These parts include fluids, filters, tools, and other essential items that are designed to help you maintain and service your Generac standby generator.

I listed the most common Generac generator maintenance kits below:

6485 Generac Generator Maintenance Kit
6484 Generac Generator Maintenance Kit
Evolution Series Generator Maintenance Kit

As a quick tip, I use the gentek power forum for all my generator questions. The folks on this forum help answer questions, locate replacement parts, and much more.

Factors Affecting Oil Change Frequency

The frequency of oil changes and periodic maintenance for generator owners will depend on several factors:

  1. Type of Generator: Standby generators typically require an oil change every 200 hours of use or at least once every 2 years. Meanwhile, portable generators require more frequent changes. Generally, portable units require an oil change after every 100 hours of use or at least once per year.
  2. Hours of Runtime: The more your generator runs, the more frequently you’ll need to change the oil. Generators used for occasional power outages might require fewer oil changes compared to those used for extended periods.
  3. Load and Usage: If you’re using your generator to power heavy loads or industrial equipment, the engine works harder, leading to more frequent oil changes. Lighter loads might allow for longer intervals.
  4. Oil Type: The type of oil you use in your generator matters. Synthetic oil, such as SAE W-30 oil, tend to have longer lifespans and can withstand higher temperatures.  Furthermore, this may allow you to extend the frequency of oil change.
  5. Operating Conditions: Harsher operating conditions, such as high temperatures or heavy loads, may necessitate more frequent oil changes.

Some modern generators, like the Honda EU series, come with maintenance reminder systems that use engine hours to prompt you for routine maintenance, including oil changes.

Importance of Regular Oil Changes in Your Generac Generator

First, oil is the lifeblood of your Generac generator.

It keeps the engine parts lubricated, reduces friction, maintains the temperature, and prevents the buildup of harmful substances. 

Over time, oil breaks down and becomes contaminated.
This leads to reduced performance and potentially costly repairs.

In essence, regular maintenance such as oil changes, air filter changes, and new spark plugs extend the lifespan of your generac generator.
These maintenance activities keep your Generac generator running efficiently and extend its lifespan.

How To Change Oil in Generac Generators

How Often to Change Generac Generator Oil
  1. Gather Supplies: First, ensure you have a fresh oil filter, the appropriate type of oil (as per the owner’s manual), and any other tools required.
  2. Prepare the Generator: Next, turn off the generator, allow it to cool, and disconnect the spark plug wire for safety.
  3. Drain Old Oil: Then, place a container beneath the oil drain plug, remove the plug, and let the old oil drain completely.
  4. Replace the Oil Filter: Remove the old oil filter and replace it with a new one. Lubricate the gasket of the new filter with some fresh oil before installation.
  5. Add Fresh Oil: Pour the recommended amount and type of oil into the oil fill port. Check the oil level using the dipstick and adjust as needed.
  6. Dispose of Old Oil: Finally, ensure you dispose of the old oil and oil filter properly at a recycling center or in accordance with local regulations. Additionally, your local auto parts store

Generator Maintenance Tips

Maintaining a back-up home generator is a good idea to ensure it operates reliably when needed during power outages.

Here’s a comprehensive list of maintenance tasks and service schedule.

Read the Owner’s Manual

Become familiar with the manufacturer’s recommendations and guidelines for maintenance specific to your whole-house generator model.

Regular Start and Exercise

Run your generator for about 20-30 minutes every month with a partial load. This exercise helps keep the engine components lubricated and ensures the generator is ready for longer periods of operation.

Change the Oil and Install New Oil Filter

Follow the manufacturer’s recommendations for oil change intervals.

Typically, whole-house generators require oil changes every 100 to 200 hours of operation.
Replace the oil filter along with the oil.

Check Oil Levels

Regularly check the oil level using the dipstick and maintain it within the recommended range.
Low oil levels can damage the engine.

Inspect the Air Filter

Examine the air filter regularly and clean or replace it as needed to ensure proper airflow and combustion efficiency.

Test the Battery

Check the battery charge and condition regularly. Clean the terminals and connections to prevent corrosion.

Fuel Maintenance

Monitor the fuel level and quality.

If using gasoline, consider changing the fuel filter and adding a fuel stabilizer to prevent fuel degradation.
A diesel generator may have different fuel filters and maintenance kit.

Cooling System Inspection

If your generator is liquid-cooled, inspect the coolant levels, hoses, and connections regularly.
Ensure the cooling system is functioning properly to prevent overheating.

Exhaust System Check

Inspect the exhaust system for leaks or damage.
A well-functioning exhaust system is essential for safe operation.

Automatic Transfer Switch (ATS) Test

Regularly test the ATS to ensure it can seamlessly switch between utility power and generator power when needed.

Monitor Warning Lights and Gauges

Keep an eye on the generator’s control panel for any warning lights, alerts, or abnormal readings. Address any issues promptly.

Keep the Area Clean

Clear the area around the generator of debris, leaves, and other obstructions. Ensure proper ventilation for the generator.

Lubrication and Greasing

Lubricate moving parts and components as recommended by the manufacturer.

Load Testing

Occasionally perform load testing to ensure your generator can handle the expected electrical load during an outage.

Professional Maintenance

Schedule annual or bi-annual professional full service maintenance by a qualified technician.
They can perform comprehensive inspections, tests, and address any maintenance or repair needs.

Record Keeping

Maintain a detailed maintenance log that includes tasks performed, dates, observations, and any repairs. This log will help you track maintenance and plan for future tasks.

Winterization (if applicable)

If you live in a region with cold winters, follow the manufacturer’s recommendations for winterizing your generator to prevent freezing and damage.

By adhering to these maintenance tasks and the manufacturer’s guidelines, you’ll ensure your whole-house home generator provides uninterrupted power during extended power outages.

Regular maintenance not only prolongs the generator’s lifespan but also safeguards your home’s comfort and safety during critical times.


In conclusion, I hope you learned how often to change generac generator oil along with other generator maintenance tips.
Regular oil changes are a cornerstone of proper maintenance for your Generac generator.

By establishing a consistent maintenance routine and using high-quality oil, you can ensure your generator is always ready for use and lasts for many years.

Remember, the frequency of oil changes can vary based on the type of generator, the oil used, and the operating conditions. 

A well-maintained generator will provide reliable power during crucial times and extend the overall lifespan of the equipment. 

Remember, consulting the owner’s manual and performing routine maintenance is the easiest way to keep your generator running smoothly, ensuring you’re prepared for any power outage that comes your way.

Related Posts:

How often should I change the oil in my Generac generator?

Generally, it’s recommended to change the oil every 100 hours of operation on portable generators and every 200 hours on whole house generators.

The frequency of oil changes for your Generac generator depends on several factors, including the type of oil, hours of usage, load, and environmental conditions.

Consult your generator’s owner’s manual for specific guidance tailored to your model.

Can I use synthetic oil in my Generac generator?

Yes, you can use synthetic motor oil in your Generac generator. Synthetic oils, such as SAE 5W-30, offer better high-temperature stability and longer-lasting performance compared to conventional oils.

Using synthetic oil may allow you to extend the oil change intervals, but always refer to the owner’s manual for oil recommendations and change intervals.

How do I know when it’s time to perform routine maintenance on my Generac generator?

Many Generac generators come with maintenance reminder systems that use engine hours to prompt you for routine maintenance, including oil changes, air filter replacements, and spark plug checks.

If your generator is equipped with this feature, it will provide notifications.

Additionally, consulting your generator’s owner’s manual for a maintenance schedule is a reliable way to stay on top of routine maintenance tasks.

How do I clean or replace the air filter in my Generac generator?

Cleaning or replacing the air filter is an essential part of generator maintenance.

To clean the filter, gently tap it to remove loose debris or use compressed air to blow out the dust.
If the filter is heavily clogged, it’s best to replace it.

Refer to your generator’s owner’s manual for specific instructions on locating and servicing the air filter. Regular air filter maintenance ensures proper airflow to the engine and helps maintain optimal performance.

Remember, the owner’s manual is a valuable resource for answering specific maintenance-related questions for your Generac generator model.
Proper maintenance, including regular oil changes, air filter cleaning or replacement, and following the manufacturer’s guidelines helps keep your generator running smoothly and reliably during power outages.