Efforts by the U.S. Congress to cap the amount of ethanol blended with the U.S. fuel supply appear to be gaining momentum.
The current Renewable Fuel Standard, passed as part of the 2007 Energy Independence and Security Act, has proven increasingly unpopular among certain legislators.
But ardent support from the renewable-fuels industry and the Environmental Protection Agency (EPA) has kept it in place thus far.
The Renewable Fuel Standard, written before a steady rise in corporate average fuel economy was enacted, requires specified volumes of ethanol to be blended into the national fuel supply.
A bill currently circulating in Congress would cap that volume at a lower amount than what the EPA is likely to prefer, according to Bloomberg.
The Food and Fuel Consumer Protection Act of 2016 calls for the amount of ethanol blended with the fuel supply to be capped at 9.7 percent.
Big square baler harvesting wheat straw for production of cellulosic ethanol
In May, the EPA proposed increasing the amount of ethanol to 18.8 billion gallons, or 10.44 percent of the national fuel supply, according to Hemmings Daily.
This House bill currently has 117 supporters, according to Bloomberg, but without further action, it will expire at the end of the current Congressional term.
However, Bloomberg suggests, legislators expect the incoming Trump Administration to be receptive to lower ethanol quotas.
President-Elect Trump has given mixed signals regarding his position on the ethanol mandate.
Earlier this year, he told the Iowa Renewable Fuels Association that the ethanol mandate should be increased, but a fact sheet published by his campaign in September called for ending ethanol blending.
Meanwhile, the EPA recently began a public comment period for a proposed rule that would permit a greater variety of ethanol-gasoline blends to be delivered to consumers.
FlexFuel badge on E85-capable 2009 Chevrolet HHR
Currently, E85—a blend of 85 percent ethanol and 15 percent gasoline—is approved for use in "flex-fuel" vehicles specially equipped to burn the fuel.
But the EPA wants to expand that "flex-fuel" category to include blends of 16 to 50 percent ethanol, in rules it aims to finalize by next December.
The agency hopes this will encourage more interest in both flex-fuel vehicles and the costly "blender pumps" that are required to add more ethanol into standard gasoline.
In addition to E85, E15 has been approved for all cars built in 2001 or later, although some carmakers still haven't hardened all their vehicles to use that fuel.
Most gasoline stations now dispense E10—a blend of 10 percent ethanol and 90 percent gasoline—as their default fuel, though pure gasoline is still available at select pumps.