The American Petroleum Institute and the American Fuel and Petrochemical Manufacturers submitted joint comments to the Environmental Protection Agency June 28 on proposed Tier 3 standards, saying that the rule would cost the industry $10 billion. The National Association of Clean Air Agencies commented that the agency should finalize the rule by December to ensure compliance can be reached by the 2017 implementation date. Both comments urged the agency to use E10 as a certification fuel rather than the proposed standard of E15.