The markets for ethanol and other renewable fuels, including biodiesel, would get a boost under an EPA proposal announced last week. Under the proposed Clean Air Act rule, renewable fuels would have to make up 3.71% of all gasoline sold or dispensed in the U.S. beginning in 2007, although producers and blenders are allowed to use more. This percentage is up from the default standard of 2.78% established in the Energy Policy Act of 2005, a limit that will remain in effect through 2006. According to EPA, the proposed higher standard includes a credit and trading system that would provide flexibility, allowing renewable fuels to be used in the greatest amounts in areas of the nation where they are most economical. EPA says about 4.5 billion gal of renewable fuels will be used in the U.S. as motor fuel during 2006. The agency estimates that on average, the proposed increase in renewable fuels will cost between 0.3 and 1 cent per gal of gasoline.