The Environmental Protection Agency should move quickly on proposed adjustments to the Renewable Fuel Standard, as the Nov. 30 deadline for the rule nears, said Bob Greco, the American Petroleum Institute's director of downstream activities. The agency said it will come up with a more sensible proposal as it has acknowledged the concerns with the blend wall, he said. Greco also believes that cellulosic ethanol production will continue to lag. "The problem is these fuels are not commercially viable yet. We have always said that if you're going to set a mandate you ought to base it on actual production and the actual production isn't there in the volumes that Congress and EPA mandated," he said.