Ethanol is an organic solvent that affects classic cars in many ways, all having to do with the fuel system. In and of itself, it has the ability to corrode our gas tanks, but so far this does not seem to be a direct problem. This is likely because it is not in high enough concentrations to cause harm and/or because it has not been in the tanks long enough to cause harm.
There are, however, several ways that we are seeing the direct impact of ethanol in our fuel. First, it has the ability to break up the varnish and sludge that has sat undisturbed in our classic cars gas tanks for many decades. I don’t have to tell you what happens once this material starts moving through the fuel lines and into the fuel system.
Second, the ethanol has the ability to soften and deteriorate the gaskets and seals which are made of materials that were in use prior to about 1990. That’s why it’s OK to use it in our newer cars. Once these gaskets and seals begin to deteriorate they can leak and will also contribute to clogging the fuel system, as well as affect the way our engines run.
Third, ethanol is hygroscopic, or hydrophilic, depending on which expert you ask. But for us classic car owners it simply means that it absorbs water. Unlike modern cars, the fuel systems on our classic cars are not sealed, so they have the ability to absorb significant amounts of water from the atmosphere. Water that is kept in suspension in our fuel is not necessarily a bad thing. The problem is that ethanol absorbs moisture into the fuel but then lets it separate out, where it settles at the bottom of the tank. Besides having an adverse affect on the way the engine runs, this moisture can corrode our fuel tanks and other parts of our fuel system. So although the ethanol itself is not corroding our fuel tanks (yet) it is indirectly causing corrosion.
So the big question is…..What can we do to prevent the ethanol in the gasoline from harming our classic cars? There are no simple answers.
You can eliminate the entire problem by using gas that does not contain ethanol, but the only source that I’m aware of is aviation fuel. Is it realistic – or even affordable – to drive to the airport every time you need gas?
“Dri-Gas” products are reasonably good at dealing with the moisture problem by keeping the moisture in suspension so that it can be easily burned with the fuel.
To deal with the corrosive nature of ethanol we can look to the marine industry which started suffering from the effects of ethanol virtually the moment it was introduced to marine fuel. They responded with additives such as “Sta-Bil Marine Formula” which does a good job of combating corrosion as well as enabling your fuel to last longer.
There is no question that ethanol can harm fuel systems over time, but no one really knows to what extent or exactly how long will it take. Ethanol has been in regular use for almost a decade now. Almost immediately upon its introduction, problems with certain types of engines such as lawn mowers and older motorcycles began to appear. I think that this is because they have much smaller fuel tanks, and fuel lines, and fuel passages through the carburetor, so the effects of the ethanol are magnified. I can’t tell you how many carburetors I’ve had to rebuild on antique motorcycles using new materials that are designed to be resistant to ethanol.
The good news is that I haven’t seen the problem in any measurable amount on classic cars. Perhaps this is because the fuel systems are large enough to deal with the effects of ethanol without outside intervention. Or perhaps next year we’ll all be rebuilding our entire fuel systems. Only time will tell. One thing is for sure. A can of “Dri-Gas” and “Sta-Bil” every few tank fill-ups certainly can’t hurt.
Contact Steve: steve@stevelinden.com