Prevent Ethanol Fuel Damage

Learn about problems associated with ethanol in pump gasoline and how to prevent difficult engine starts.

Preventing Ethanol Damage to Mantis Tiller Engines

Q. Why is ethanol bad for small engines?

A. The ethanol added to gasoline attracts water. Humidity and poor storage can accelerate this problem. Over time this water can separate from the gasoline; this water-ethanol blend is highly corrosive to some components in small engines. Gasoline breaks down over time and becomes gummy, causing starting issues made worse when fuel is old and left in the tank or container between seasons.

Q. Gas stations sell fuel with ethanol that we use in our cars; what is the difference?

A. Cars are designed to process this fuel without damaging their engines. In addition, cars are refueled regularly and therefore the gasoline does not have time to cause problems like it does in small engines that are run much less frequently.

Pro Tips:

  • Packaged or engineered fuels (such as TruFuel®) are specifically designed for small engines and open containers last for up to two years. Always follow the manufacturer’s recommendations for shelf life and storage instructions.
  • Engineered fuels contain no ethanol and have a longer shelf life
  • Pump gasoline (with or without ethanol) has a shelf life of only 30 days when stored properly in an approved container

Additional Resources: