The U.S. has gone from importing 60% of its oil in 2005 to 41% today, thanks to the Renewable Fuel Standard, said Bob Dinneen, Renewable Fuels Association president and CEO. The RFS has encouraged biofuels investment and improved efficiency. The industry's biggest challenge ahead is market access for E15, he said. "We can probably produce more ethanol, but it needs a market. We need more flex-fuel vehicles, more places to sell, more marketers willing to offer E15 to consumers," Dinneen said.