Whatever brand of gasoline you are buying most likely is blended with ethanol. Driving green or so the government wants you to believe has it good points and its bad that is until you consider the effect ethanol and flex fuels have on vintage cars.

The chemistry of the matter is simple. Ethanol is a solvent. It absorbs water, loosens sludge, varnish, and dirt in the fuel tank, and after picking up all this gunk, it becomes heavier than gasoline and sinks to the bottom of the tank where the fuel pick up is located. This gunk will clog fuel lines, carburetor jets, and may be incompatible with rubber parts and corrosive to some metals.

There are lots of rumors going around that ethanol blends cause fuel pump diaphragm failure. True or not, several leading vintage car restores are recommending the use of 100 octane racing fuel over pump gas with ethanol blends. The cost difference these days is irrelevant.

A recent study was commissioned by a vintage car insurance company representing some 600,000 owners. Kettering University is conducting the research to determine the effects of ethanol in old cars with preliminary results are expected mid summer 2008. (We will report the findings once released.)

Experts suggest that owner’s drain and clean their fuel tanks, apply a tank sealant that is impervious to ethanol, replace fuel filters, and always use a stabilizer like Sta-bil if your car is stored for any length of time. If you drive your Porsche routinely, the effect will likely be lessened than if driven only on rare occasions when you will no doubt experience one of the problems noted above. And remember, seasonally blended fuels are stable for only about six months.