Drive an older car or own a moped, motorcycle or lawnmower? Depending on which fuel pump you use, the Environmental Protection Agency (EPA) is requiring that you buy at least four gallons of fuel—although some vehicles that require the minimum four gallon requirement don’t even have a four gallon fuel tank.

According to a recent letter by the EPA to the American Motorcyclist Association, motorists buying E10 fuel (a mixture that contains 10 percent ethanol) from a hose that also supplies E15 fuel (a mixture that contains 15 percent ethanol) must buy at least four gallons to protect customers following behind. Ethanol is hard on engines and less efficient than regular gasoline. E15 can even cause engine failure in smaller or older engines. So if you’re using a blender pump to buy E10 that sells both E15 and E10, the residual amount of E15 left in the hose from the previous customer could cause significant damage to those smaller and older engines—unless you purchase at least 4 gallons.

In 2010, the EPA began allowing up to 15 percent of ethanol to be blended into gasoline for cars and light-duty trucks model years 2007 or newer. A year later, the agency included model years 2001 to 2006. Automotive equipment manufacturers warn that the EPA’s acceptance of E15 is premature and conducted tests that show out of eight engines tested, “two popular gasoline engines used in light-duty automotive applications of vehicles from model years 2001 through 2009 failed with mechanical damage when operated on intermediate-level ethanol blends (E15 and E20).”

The controversy over E15 and the 4 gallon minimum fuel requirement are part of a larger problem: the ethanol mandate. The ethanol mandate, also known as the renewable fuels standard, was created in 2005, increased in 2007, and requires the production of 36 billion gallons of ethanol by the year 2022.

Slower demand for gasoline, however, has made the ethanol targets for each year difficult to meet. So now producers are over-supplying a government-created market. Instead of working to develop a product that consumers want to purchase, ethanol interests want the government to create an even larger artificial market for ethanol. One way was to encourage the EPA to allow for a higher percentage of ethanol to be blended into gasoline.

Allowing more ethanol to be blended into our fuel mixture isn’t necessarily the problem. We should encourage a competitive fuel market by removing regulatory barriers that prevent alternative fuels from reaching the market. Fuel choice and a more diverse fuel market can be beneficial when it’s driven by producers and consumers in a free market. The problem occurs when the federal government creates artificial markets through mandates. Inevitably, such policies lead to unintended consequences. In the case of the ethanol mandate, these consequences include potential engine damage and minimum fuel requirements.

Congress established and President Bush signed into law the ethanol mandate to address high fuel prices, dependence on foreign oil, and environmental concerns with the hope that renewable technologies could stimulate the economy. Sound familiar?

Thanks to Congress’ efforts to solve perceived problems that could have and should have been left to the market and American ingenuity to tackle, Americans have one more real problem to add to the heap of real problems the ethanol mandate has created.

On top of the E15 debacle, the ethanol mandate is driving up food prices, has caused more environmental harm than good, and is driving up fuel prices. Although fuel that is 85 percent ethanol appears cheaper at the gas station, it is less energy dense, so you’re actually paying more. In essence, for every problem the ethanol mandate was supposed to address, the opposite effect is occurring. This is why politicians are calling for waiving the ethanol mandate and the European Union is scaling back the amount of biofuels developed from food crops.

A lot of questions remain as to what fuel is safe for a motorist to use, but one thing is certain: Congress needs to repeal the ethanol mandate.