To dispose of old gasoline, add it to the tank of a mower, car or truck that burns gasoline, provided the gas is not older than the engine manufacturer's specifications. Do not pour the gasoline into a storm drain, onto the ground or into a dumpster, as these actions can be hazardous.
- Check the manufacturer's recommendations on your engine
Read the owner's manual for your car, truck, lawn mower (or other gas engine) to determine the maximum safe storage time for gasoline in that engine. Storing gas in containers that are cool, below 80 degrees Fahrenheit, and around 95 percent full maximizes its shelf life.
- Add the gas to your engine
If you are certain that the gas has not been stored longer than the recommended time period, pour the gasoline from the storage tank into the engine. Choose the engine that has the least level of risk involved, such as using the lawn mower rather than the engine of your car.
- Dispose safely of gas that is too old for use
Contact your city's sanitation or waste management department to determine the proper method for disposal of old gasoline in your community, as different cities develop different protocols. Contact the sheriff's office or fire department if you live in a rural area beyond incorporated city limits to find the regulations for safe disposal.