<P> Gasoline containing up to 10 % ethanol began a decades - long growth in the United States in the late 1970s . The demand for ethanol produced from field corn was spurred by the discovery that methyl tertiary butyl ether ( MTBE ) was contaminating groundwater . MTBE 's use as an oxygenate additive was widespread due to mandates in the Clean Air Act amendments of 1992 to reduce carbon monoxide emissions . MTBE in gasoline had been banned in almost 20 states by 2006 . Suppliers were concerned about potential litigation and a 2005 court decision denying legal protection for MTBE . MTBE 's fall from grace opened a new market for ethanol , its primary substitute . Corn prices at the time were around US $ 2 a bushel . Farmers saw a new market and increased production . This demand shift took place at a time when oil prices were rising . </P>
<P> Gasoline containing up to 10 % ethanol began a decades - long growth in the United States in the late 1970s . The demand for ethanol produced from field corn was spurred by the discovery that methyl tertiary butyl ether ( MTBE ) was contaminating groundwater . MTBE 's use as an oxygenate additive was widespread due to mandates in the Clean Air Act amendments of 1992 to reduce carbon monoxide emissions . MTBE in gasoline had been banned in almost 20 states by 2006 . Suppliers were concerned about potential litigation and a 2005 court decision denying legal protection for MTBE . MTBE 's fall from grace opened a new market for ethanol , its primary substitute . Corn prices at the time were around US $ 2 a bushel . Farmers saw a new market and increased production . This demand shift took place at a time when oil prices were rising . </P>
when did they start putting ethanol in gas
when did they start putting ethanol in gas
the late 1970s
the late 1970s