Dual fuel generators can run on either gasoline or propane (LPG). These units allow you to either choose between running at full power, on gasoline, or on a derated, but more eco-friendly power source, propane. Propane is generally cleaner to run compared to gasoline, since it has a lower carbon content and burns in a cleaner fashion. These generators can be particularly useful when gasoline is not easily accessible or when you need to store fuel for the long term. Unlike gasoline, propane does not degrade over time.