Small Engines
Small Engines

Even a Small Change Makes a Big Impact

There’s no denying that ethanol gets a bad rap in the world of small engines. We’re constantly bombarded with suggestions that ethanol is the source of engine-part corrosion and that using ethanol blends of any kind can ultimately destroy small engines and void their warranties. These claims are simply not true.

So, what’s the truth?

The most common myth associated with ethanol and small engines are the hardening and deterioration of gaskets, seals and hoses. The reality, however, is that gasoline and the toxic components added to gas are often the real culprits of small-engine problems.

These toxic components are called “aromatics,” which are all different types of benzene, and they make up roughly 25 percent of consumer gasoline. Research shows that many of these small-engine issues are the same with E0 (no ethanol) and E10, which proves aromatics – and not ethanol – cause the deterioration of gaskets, seals and hoses.


  • Does ethanol harm or corrode small-engine parts?

    Ethanol is often blamed for the hardening and deterioration of gaskets, seals and hoses. However, the toxic components in gasoline are actually causing the problem – not ethanol. Research shows that many of these small-engine issues are the same with E0 (no ethanol) and E10, which proves aromatics cause the deterioration.

  • Why is water the real danger to your fuel system?

    Small engines and older applications generally do not have sealed fuel systems. Leaving these engines out in the weather exposed to rain and moisture will allow water to build up in the fuel tank. Also, covering your equipment with a tarp or plastic will allow moisture to accumulate under the cover and condense in your fuel system. With or without ethanol in your fuel, this moisture can create significant issues with engine parts. The more you can prevent your engine’s exposure to water, the longer it will last without needing service.

  • Can ethanol be used with any small engine?

    This site does not recommend operating any small engine, marine or older on-road vehicle made prior to 1996 on blends above E10 (10 percent ethanol). This is not necessarily due to materials compatibility, but instead to the lack of a computer and sensors in those engines to control the fuel and air mixture.

  • Is ethanol an aggressive solvent?

    Many say ethanol is a solvent, but ethanol is not the most aggressive solvent in gasoline. Instead, a common solvent sold at Lowe’s or Home Depot called Xylene (toluene sold in the past) is often more damaging – and it generally makes up to 25 to 30 percent of consumer gasoline.

  • Should small-engine owners drain their gas in the off-season?

    Yes. It is beneficial to drain your gas if you’re storing it for more than a few months. If you don’t, gasoline can evaporate through the carburetor, which can cause residue to plug the passages. Also, gasoline can permeate through plastic and fuel lines over time, causing it to go stale and making it difficult to start the engine when taking it out of storage. Some engines have a shut-off valve that allows the engine to be operated until the fuel is run out of the line and carburetor. The gasoline can stay in the fuel tank, but over time, it will lose volatility. Some consumers have preferred to leave the gasoline in the fuel system to lessen the chance of seals and gaskets shrinking and hardening. Leaving the fuel in the system has some concerns, but many have not had problems doing so. However, it is best to use newly purchased or fresh gasoline in equipment that’s been stored for any extended period of time. The best advice here if you are unsure, ask a trusted mechanic.

    You should also be aware that the quality of your gas can makes a difference. Cheap plastic gasoline containers can permeate significant amounts of gasoline right through the plastic.  Higher quality containers can extend the storage life of gasoline as well as reduce toxic fumes. Fueling the Truth found these manufacturers of gasoline containers use high quality plastic technology to significantly reduces the rate of gasoline permeation.

    1. Scepter Manufacturing, LLC
    2. Scepter Canada, Inc.
    3. No-Spill Inc.
    4. Reda Innovations
  • How can you improve the quality of your gasoline?

    Improvements to gasoline quality can only happen if consumers are aware of the issues caused by gasoline additives and demand change for better quality. Improved gasoline will benefit your car, boat or any other smaller engine equipment (like lawn mowers and trimmers). More important, it will benefit your family, since regular gasoline emits a host of toxic emissions. Many are unaware today of the very real dangers of toxic benzene related aromatics in our gasoline.

  • What if your mechanic blames ethanol?

    It is not in our interest to be critical of mechanics, but many mechanics rely on what they hear. They are likely very busy and don’t have the resources or time to do their own soak testing. When we provided fuel with and without ethanol to local small-engine shops for soak testing, they were then able to see it wasn’t ethanol causing the problems.

    The following statement was written by a major engine builder for the intent of putting this warning into gasoline standards. Today, the oil industry has again objected to bring this to a vote.

    “Variability in gasoline and gasoline-oxygenate blends composition, particularly aromatics content, may result in materials incompatibility problems. Some types of elastomers and plastics used to make gaskets and seals may swell with higher concentrations of aromatics in fuel and then shrink with very low concentrations of aromatics, which may result in a compromised ability to seal.”