Frequently asked questions about air-cooled home standby generator oil.
This article addresses frequently asked questions about oil for air-cooled home standby generators.
Environment
This article applies to most air-cooled home standby generators.
FAQ
For model specific information consult your owner's manual. See Where can I find a user manual or other documentation for my home standby generator?
1. What does Motor Oil Do?
- It circulates through the engine to keep it cool and prevent wear by acting as a lubricant. It helps prevent corrosion, keeps surfaces clean, and seals the engine.
- Synthetic oil is tailored for higher temperature and pressure.
2. What is the difference between Regular and Synthetic oil?
- Both conventional and Synthetic oils are derived from petroleum but can be very different products.
- Conventional oil is refined from crude oil.
- Synthetic oil is also refined, but then it’s distilled and purified so that it contains fewer impurities. It also contains additives intended to help keep engines cleaner and protect it from damage.
- Regular oil is more apt to pick up deposits and form sludge
- Synthetic oil has increased engine protection and performance at low and high temperatures.
3. What type of oil should I use in my home standby generator?
- The specific type of oil recommended can vary depending on the run hours and climate in which it operates; see
- What type of oil should I use in my home backup generator?
- Air-cooled home standby generators are shipped with a conventional oil specially designed for the break-in period, after which synthetic 5W-20 GEO is recommended.
- The type of oil depends on climate temperature because oil viscosity, or thickness, is affected by temperature.
4. How often should I change the oil in my generator?
5. How do I check the oil level in my generator?
6. What happens if the generator runs out of oil?
All air-cool home standby features a low oil pressure fail-safe, which will trigger a shutdown if the oil levels/oil pressure is too low. See the following article for more information:
7. Can I keep adding oil when running low without doing an oil change?
- Definitely top off oil levels in an emergency low-oil situation, but ALWAYS follow the required service maintenance intervals in the manual.
- When adding new oil to bring oil levels back to normal, the old, sludgy, dirty oil doesn’t disappear – It just mixes with the new, fresh, clean oil. This puts more stress on the new oil and keeps it from working as well as it could.
8. Can I mix different brands or types of oil in my home standby generator?
Example: If I normally use a 5W-30 or 10W-30 non-synthetic oil, can I add a 5W-30 synthetic? What if my Generator is running low and that’s all I have available during an outage?
It is not recommended to mix oils; however, in an emergency outage situation when no alternative exists, it is possible to mix oil for limited emergency use. Mixing different types of oil will not harm your engine in the short term, but it is important to perform a full oil change as soon as possible. Most oils are compatible with each other because many are a blend of natural and synthetic oils.
Mixing Motor Oil
- It’s always better to stick to one grade of oil till you decide to change your oil completely.
- It’s only recommended to top off your generator with different oil grades when running low and similar oil is not available.
Possible Negative Effects
- It’s recommended to not mix two different brands of oil as the additives may or may not be compatible.
- The additives in synthetic oil may have limited or no effect when mixed with regular engine oil.
- Mixing different synthetic oil blends could actually have negative effects in the long term as the additives may react.
See If My Generator Has Been Running 5W-30 Synthetic Oil, Can I Switch Over to Conventional? for additional information.
9. What do I do if I overfill the oil in my generator?
10. How much oil does a generator typically need?
Oil capacity varies by unit. Exact capacity specifications can be found in the owner's manual and specifications sheet.
See the following articles for more information.
