Brought to you by the National Association of Automobile Clubs of Canada

Ethanol is hygroscopic, which means it absorbs water more easily than gasoline. That leads to water condensation and often rust inside fuel tanks.  Carburetor fuel bowls and fuel lines where air spaces are present also collect water. The water content in fuel will also swell up the paper filter media inside fuel filters not specifically designed for flex fuels and can thus restrict fuel flow at the filter.

Ethanol also erodes fiberglass tanks, rubber hoses and plastic fuel lines. It     contributes to rust in fuel systems by creating condensation in the unfilled portion of gas tanks. It will also dissolve varnish and rust in steel fuel components. These dissolved ingredients sit in the bottom of gas tanks until they are removed or they will enter the fuel system if the fuel level in the tank gets too low.

So, what is a Classic Car or Hot Rod owner to do? Especially when their car is sitting unused in the garage more than it is on the road? ( An NAACC survey reports collector vehicles are driven on average 800 miles per year. )

Several recommendations of things you can do that should help come from OE marine manufacturers who have been also battling these ethanol-related fuel problems:

  • Replace any plastic or rubber fuel lines with ethanol-resistant hose or nylon tubing.
  • Install a water separator filter in the fuel line leading to the carburetor. Water collects in the filter and can be removed periodically.
  • Replace any fiberglass tanks with steel or aluminum.
  • Ensure that any O-rings in the fuel system are also ethanol-compatible.
  • Keep your tank as full as possible to prevent air space where condensation can form.
  • Use specific ethanol-compatible fuel storage additives. These are normally blue in color. Regular fuel stabilizers will not work unless they are labeled ethanol fuel-compatible.
  • Shop around for a marina or service station that does not pump E10 or E85. The USA still supplies non – Ethanol Fuel.
  • Use to locate fuel sources.
  • Vent your fuel system during storage for extended periods; the moisture your fuel system might absorb from the outside will be less than the moisture created in the air space inside 
  • Use a fogging solution in your carburetor during storage to prevent condensation from collecting in fuel bowls.
  • Regular dry gas is ethanol-based and will only make the problem worse. Isopropyl-based additives actually combine with the water molecules and remove moisture through the combustion chamber.
  • Dry gas is an alcohol-based additive gas used in automobiles to prevent water from freezing in water-contaminated fuels, thereby restoring the combustive power of gasoline spoiled by water. Dry gas is added to the fuel tank and binds to the water to burn it off, and typically contains either methanol or isopropyl alcohol. The NAACC suggests not to use Dry Gas.
  • Use of a flex fuel-compatible fuel filter where possible will prevent degradation of the paper media in your filter by water in the fuel system.

SEMA/SAN has also made ethanol in gasoline one of its legislative priorities.

Credit for this article should go to Tech 101 – Ethanol in gasoline and its effects on collector cars | Hemmings and the author of the article Jim O’Clair The NAACC has added to this article and thanks Mr. O’Clair for his outstanding work.

Article by Jim O ‘Clare – Brought to you by the NAACC