Although President Donald Trump indicated he favored year-round sales of E15 fuel, the U.S. Environmental Protection Agency did not grant a waiver allowing fuel containing 15 percent ethanol to be sold during the summer months.

Restrictions began June 1 and end Sept. 15.

E10—fuel containing 10 percent ethanol—is sold year-round under an EPA waiver.

The E15 regulation is tied to Reid Vapor Pressure, which is a measure of how quickly fuel evaporates. Volatility and evaporation rate affect the overall emissions of fuel, and higher temperatures increase the rate of evaporation.

The ethanol industry has been lobbying for an E15 waiver. But the AMA opposes a waiver, because none of the motorcycles and ATVs in operation across the country are approved by the EPA to operate on E15 or higher ethanol blends.

Misfueling with E15 is a significant concern during popular summer riding months.

The AMA also fears that increasing the availability of E15 and allowing year-round sales will reduce the availability of E10 and fuel with no ethanol content (E0), which is needed for older and vintage machines.