The short answer
Gasoline gives the most watts but ages in storage and sells out after storms; propane stores well but gives somewhat fewer watts; natural gas can avoid refuelling if the line stays up but needs a connection. Size the generator against the rating for the fuel you will actually use.
Side by side
| Gasoline | Propane | Natural gas | |
|---|---|---|---|
| Storage | Ages; use stabilizer and rotate | Tanks keep well | No storage; depends on the utility line |
| Watts | Highest rating | Usually somewhat lower | Usually lower again |
| Refuelling | Cans; pump availability in a storm | Swap or refill tanks | None while the line is up |
| Main risk | Spills, fumes, theft | Tank handling, regulators, placement | Line damage or shutoff; a qualified person must make the connection |
Makers publish per-fuel watts and runtimes on their specification pages; our dual-fuel generator table shows which models list more than one fuel.
Choosing
- If you can store propane safely, a dual-fuel unit gives long-term fuel stability and a gasoline fallback.
- If you have natural gas service and want to avoid refuelling, a tri-fuel unit with a properly made natural-gas connection can run as long as service continues — have a qualified person make the connection.
- Compute runtime with the fuel calculator for the fuel you plan to use.
SafetyAll fuels bring fire risk and carbon monoxide risk from the exhaust. Store and handle fuel as the maker and local rules direct, and keep the generator outdoors.
Figures marked as Wattstanding calculations show their working; product figures come from the sources on each product page. How we work