On Monday, the U.S. Environmental Protection Agency got one step closer to putting E15 (gasoline with 15% ethanol) on the market. After a three-year investigation and approval of health effects testing of the fuel in February, the EPA approved E15 as a registered fuel.

"Today's EPA decision clears yet another major hurdle in bringing E15 to the marketplace. States in the Midwest have begun to address their regulatory requirements and perhaps as early as summer we could see E15 at fuel stations in the Heartland of America," said Bob Dinneen, president and CEO of the Renewable Fuels Association.

However, since ethanol burns hotter than conventional gasoline, there are major concerns about how gasoline-powered equipment will handle the new mix. Landscape contractors are among those consumers complaining of resulting engine damage, both to small engines, like those in lawnmowers, and even older-model cars and trucks.

E15 would sell for about one dollar a gallon less than gasoline.