The American Petroleum Institute (AP), the association of oil drilling, refining, and natural gas producing companies, joined this week in signing a letter to Congress backing a move to grant year-round use of E15. Other signatories to the letter included the Renewable Fuel Association (RFA), Growth Energy, National Association of Truck Stop Operators (NATSO), the National Corn Growers Association (NCGA), and American Farm Bureau Federation (AFBF) among other producer groups. That is a major development and has segments of the industry from upstream production to downstream marketing aligned.  The Clean Air Act (CAA) of 1990 set the standards for ethanol blending with regard to its volatility in evaporating measured  by a metric...