The American Fuel and Petrochemical Manufacturers Association has filed suit to block the EPA’s approval of year-round sales of higher-ethanol blends of gasoline, arguing the move exceeded the administration’s authority.

A summertime ban on E15 (fuel with 15 percent ethanol) sales had been in place to reduce smog emissions, but the EPA said this year that E15’s impact on air quality was similar to that of E10, which can already be sold year-round.

The AMA opposes year-round sales of E15 because increased availability heightens the risk that motorcyclists may inadvertently misfuel.