Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns. 

Selecting generator oil

Generac home standby generators ship from the factory with oil already in the engine. This article provides guidance on what oil should be used after oil changes, and how often it should be changed.

Environment

This article applies to air cooled and liquid cooled home standby generators.

Which oil?

After the 25 hour break-in period (and at every interval there-after), it is recommended to use Generac's proprietary full synthetic 5W-20 Gaseous Engine Oil (GEO) for continuous use. It is specifically formulated for use in gaseous powered Generac generators.

Note: The unit comes filled with 5W-30 weight organic oil (non-synthetic) from the factory. Check oil level and add appropriate viscosity and amount of oil if necessary.

Need the oil capacity for your specific model? See here: What is the oil capacity of a home standby generator?

 

Oil	Temperature Range	Use
5W-30	Full operating range	Factory fill and break-in only
Generac Synthetic 5W-20 GEO	Full operating range	Recommended after break-in
Synthetic 5W-30*	Full operating range	Acceptable (emergency)
10W-30*	−10°F to 40°F (−23°C to 4°C)	Acceptable (emergency)
SAE 30*	> 32°F (0°C)	Acceptable (emergency)

* Use only if Generac 5W-20 GEO is unavailable and oil meets API SJ, SL, or better.

Break-in note:
The generator is shipped with conventional 5W-30 oil for the break-in period. Do not switch to synthetic oil until after the initial 25-hour oil change.

Post break-in note:
After break-in, always use Generac’s proprietary full synthetic 5W-20 Gaseous Engine Oil (GEO) whenever possible. If it is unavailable, select an acceptable alternative based on your temperature range and ensure it meets API Service Class SJ, SL, or better.

Oil changes

• Oil changes are a critical maintenance task to help prolong the life of the generator's engine. 
• Oil changes should be performed according to the generator's maintenance schedule detailed in the owner's manual: Where can I find a user manual or other documentation for my home standby generator?
• The first oil and oil filter change should be performed when the generator reaches the end of its break-in period, which is defined as its first 25 hours of operation: How do I find out how many run hours are on my home standby generator?
• The end of the break in period for the 7.5kW PowerPact is its first 20 hours of operation.
• The end of the break in period of liquid cooled generators varies. Consult the owner's manual for specifics. 
• When the generator's break in maintenance interval has been reached, an oil change and oil filter change is required: How do I perform the break-in maintenance for a home standby generator?
  

See also 

• How do I perform the break-in maintenance for a home standby generator?
• How Do I Change the Oil and Oil Filter in a Generac Air-Cooled Home Standby Generator?
• What Would Cause My Generator Oil to Turn a Milky Color?
• What is the oil capacity of a home standby generator?