Ethanol is made chiefly from corn in the United States and from sugarcane in Brazil.
 

In the United States, corn ethanol is blended into gasoline at 10% concentrations that can be burned in regular gasoline engines. A small amount of ethanol is sold in concentrations of 85% for "flex fuel" cars that can burn either gasoline or ethanol.
 

Options to expand ethanol supply include opening up the market to ethanol imports, and using advanced technology to convert corn stover (the plants and husks that are left on the field) or "energy crops" such as switchgrass to ethanol. While corn kernels are mostly starch, corn stover and switchgrass are primarily cellulose. Commercial technologies to make ethanol from cellulose are not yet available, but laboratory and pilot-scale tests are generating useful data on processing techniques.

In Brazil, ethanol is sold as a stand-alone fuel and also gets blended into gasoline at 24% concentrations.

• The share of flex fuel vehicles in new car sales in Brazil rose from 4% to 90% in fewer than five years. These cars are manufactured by the same automakers that sell to the U.S. market and entail no size, power, or safety compromise by consumers.
   
• Sugar, from which ethanol can be cheaply and efficiently produced, can be grown in about one hundred countries, many of which are poor and on the receiving end of U.S. development aid. Encouraging these countries to increase their output and become fuel suppliers, and opening our fuel market to them by removing protectionist tariffs, could have far-reaching implications for their economic development as well as our own energy security.