The Ethanol Problem

The Ethanol Problem


         When I started doing the background research needed to write an ethanol article for Injector Repair, I did not realize what I was getting into.   I knew that Ethanol had caused a lot of problems in older vehicles when it was added to the gas in the USA in the mid 2000’s, but I did not know how big of a problem it had become.  I went to many industry and government websites, and the pro ethanol sites always preached how good ethanol is, and the anti ethanol sites pointed out all the problems that had to be dealt with in order to minimize the problems in the transportation, storage, and use of ethanol.  What I have written is a lot of information, so if you want, skip to the section Precautions to Take to Minimize Ethanol Problems.  The recommendations there will minimize, but not eliminate most of the problems you can have because of the ethanol that is added to our gas in the good old USA.


Don’t forget, when you need your injectors serviced

Send ‘em in and get ‘em fixed!


 Jim of Injector Repair, LLC


       In 2007, the 822 page Clean Energy Act was passed into law by the US government.  Besides effectively banning the manufacturing and importing of incandescent light bulbs by the year 2014, the law required taxpayer funding to support a mandated increase in the production and use of bio fuels (mainly ethanol).  The law mandated that the total amount of bio fuels added/mixed to gasoline to increase from 4.7 billion gallons in 2007 up to 36 billion gallons by the year 2022.  In order to meet the usage guidelines, most states now mandate at least 10% ethanol be added to all gasoline.  Currently, the EPA has increased the amount of ethanol that can be added to fuel up to 15% (E15) for use only in vehicles manufactured after 2001.  E15 is not safe to use for many vehicles currently on the road.





       Most automobiles since 1982 were designed to be compatible for use with up to 10% ethanol (E10), and since the year 2000 most marine engines are now compatible with E10 use.  But, almost all marine engines manufactured prior to 2000 prohibit the use of any alcohol fuel.  As of 2012, automobile manufacturers only allow the use of up E10.  The use of more than 10% ethanol in your fuel will void most automobile warranties.  The only vehicles designed for the use of more than 10% ethanol are the flex fuel vehicles.  The flex fuel vehicles have special ethanol resistant fuel pumps, fuel tank sending units, fuel tanks, fuel lines, and fuel injectors!  

Link to: Research group tests show E15 damages vehicle engines



Ethanols’ Water Problem;


       Ethanol is  hygroscopic, which means that ethanol attracts and absorbs water moisture.  Ethanol mixed gasoline fuels (E10, E20, E25, and E85) can readily absorb over 40 times more water than non-alcohol gas.


       Ethanol’s affinity for water means it acts as dryer” because it readily absorbs water and holds it in suspension.  This also lets it act as a fuel antifreeze in cold weather climates.


       Phase separation occurs in E10 gas when it absorbs only 0.5% of water (3.8 teaspoons) per gallon of E10.  When 0.5% of water is absorbed into the ethanol-gasoline blend, the bonded water and ethanol will separate and dissipate from the rest of the gasoline.  The water and ethanol will drop out of the gas and you will be left with a layer of water on the bottom of the tank, a layer above that of ethanol/water mix, and above that a top layer of gasoline that is now 3 octane lower than it was when it was mixed with the higher octane ethanol.



       The remaining components of this phase separated gas are not re-mixable and should be discarded.  Phase separation is a significant problem when storing E10 more than 100 days.



Link to: Video showing phase separation of water in ethanol gas


Ethanol and Gasoline Storage Problems;           


        Ethanol mixed gasoline should not be stored long term.  Ethanol’s storage shelf life is only up to 100 days.  In 100 days or less, even under ideal conditions (low humidity, sealed fuel system), the alcohol part of the gasoline mixture will absorb enough water from atmospheric humidity and condensation to cause contamination.  Phase separation becomes a concern after 100 days.  When E10 becomes cloudy, then you know it is going bad due to water contamination.



       Problems with long term storage of ethanol gasoline are pronounced in marine applications, lawn and garden applications, and recreational vehicles, where engines are not used for extended periods of time.



       Even regular 100% gasoline degrades and oxidizes over time.  During long term storage, regular gasoline will oxidize and leave deposits of varnish, gum, and sludge in the fuel tank and on fuel system components.  If ethanol is present, these deposits will be scoured and cleaned and held in suspension in the gas.  The deposits in suspension in the gas will be brought to the fuel filter, the injector’s micro filter, and the injectors’ valve, and this can choke off an engine’s fuel supply.



       Regular gasoline’s shelf life is about 12 months due to oxidation.  If the fuel darkens then you know it has gone bad.                                                                                                        


Link to: A Study On The Causes Of Foul Fuel

Link to: Contaminated_fuel_can_wreck_havoc_on_fuel_delivery_systems


Ethanol’s Corrosive Problems;


       Ethanol is mildly acidic, and acids accelerate the corrosion process.  Ethanol’s affinity to water adds to its already corrosive nature, and is particularly corrosive to steel/iron alloys.



       Ethanol’s corrosive property is one of the reasons why it is not usually transported by refinery pipelines.  Ethanol rapidly causes serious corrosion problems in pipelines and eventually leads to cracks in the pipeline.  Ethanol is transported mostly by tanker trucks or in a limited number of specially designed high tech pipelines.



       The automotive and marine industries have mostly eliminated fuel system component failure problems due to corrosion since the 1980’s.  The use of internally coated gas tanks, stainless steel, and ethanol resistant polymers in fuel delivery components have made corrosion almost a non-issue.  Even so, using ethanol blend over 10% Ethanol (E10) in automobile and marine fuel systems can cause problems especially with vehicles manufactured prior to 2012.


Ethanol’s Plastic/Rubber Problems;


       Ethanol causes the degradation, softening, swelling and destruction of a number of polymers, elastomers, and thermoplastics. This is a significant problem in automobiles manufactured prior to 1982, and in most marine engines manufactured prior to 2000.



       This was a particularly severe problem in older marine engines where the fuel lines became soft and gummy and the fiberglass resin gas tanks slowly broke down due to the ethanol gas.  This rubber/plastic degradation issue has been addressed through the use of ethanol resistant polymers and elastomers in fuel lines, gaskets, sending units, and fuel pump components.  Even so, as recently as 2012, the American Petroleum Institute did a study on E15 when the EPA tried to get E15 allowed for widespread use.  The American Petroleum Institute‘s study found that a tremendously large number of  E10 resistant fuel pumps in many newer vehicles were not able to survive being exposed to E15.  The E15 caused the polymer parts of the fuel pumps to deteriorate and the pumps impellors would fall apart.  The EPA relented and approved E15 only for 2001 and newer passenger vehicles.  The fuel pumps and fuel level sensors that failed during testing on E15 are used on a substantial number of the 29 million 2001 to 2007 model year vehicles in use.


Ethanol’s Fuel System Cleaning Problem;          


       The Ethanol in E10, E15, and E85 is a serious solvent / degreaser / cleaner.  Ethanol scours and scrubs varnish, gum, sludge and dirt deposits out of a fuel system.  The deposits will be “held” in suspension in the Ethanol fuel and will eventually wind up in the fuel filter / main jet / fuel injectors, and can choke off an engine’s fuel supply.  This cleaning effect will normally not be a problem, and will keep every fuel system component nice and clean.  That is, until you get one or more bad tanks of fuel from a service station that has had a bad load of fuel delivered, or that does not take maintenance seriously by changing the pump filters regularly.  Before the use of ethanol, most of the gunk would sit on the bottom of your gas tank forever and adhere to the varnish / deposits in the bottom of the tank.  Now, with ethanol, any and all deposits will be lifted into the fuel, held in suspension, and will get to the fuel filter, pump, injectors, micro filter, etc. 


One bad tank of gas can lead to fuel injection problems.


Ethanol and Reduced Fuel Economy;


       There is a decrease in fuel efficiency and mpg due to the lower energy content of ethanol.  Ethanol has only 68% of gasoline’s energy in BTUs.



      • 100% Ethanol      =  76,100 BTU’s/gallon
      • E85                      =  81,800 BTU’s/gallon
      • E10                      = 111,836 BTU’s/gallon
      • 100% Gasoline    = 114,000 BTU’s/gallon       

       If your car gets 30 mpg with regular gasoline, you will only get 29.1 mpg with E10, and you only get a lousy 21.9 mpg with E85.  Supposedly the consumer will make up for the loss of mpg if the price of ethanol is significantly less than the price of gasoline per gallon.


Ethanol is an Octane Booster;          


       Ethanol is 113 octane.  Adding 10% ethanol raises the fuel’s octane by 2 to 3 points.


Ethanol Burns Cleaner;          

       Fuel containing ethanol burns more completely and reduces carbon monoxide emissions by up to 30%.




  1. The most effective precaution you can take with alcohol blended fuels (E10, E15, and E85) is to make sure you only run with new fresh fuel.
  2. Maintain a full tank, and keep as little air in the tank as possible.  Atmospheric humidity and condensation are ethanol’s biggest enemy.  The venting process of the fuel tank will bring moisture laden air into the tank.  Keeping your gas tank full will help prevent water problems and help the gasoline / ethanol mix last longer.  This also helps to prevent the older tanks from rusting.
  3. Do not store ethanol gasoline for long periods.  If you need to store a tank of ethanol fuel long term, use a high quality non-alcohol based fuel stabilizer / conditioner.  A fuel stabilizer will increase ethanol’s storage time from only 100 days up to 12 months.  At 12 months, the ethanol in the E10 fuel will absorb too much water, and the gasoline part of the E10 fuel will oxidize and deteriorate.   Sta-bil and Star tron are brands of fuel stabilizer that are widely used to condition Ethanol blend fuels.
  4. Buy your E10 from name brand stations that regularly maintain their pumps’ filtration and regularly check their tanks for contamination.



                                                                                                     Link to BG Ethanol Products



One Bad Tank of Gas Can Cause Clogged Injectors!!!!!