The US Environmental Protection Agency recently issued an emergency fuel waiver to allow E15 gasoline—gasoline blended with 15% ethanol—to be sold during the summer driving season. Current estimates indicate that on average, E15 is about 25 cents a gallon cheaper than E10.

Currently, in roughly two-thirds of the country, E15 cannot be sold from terminals starting on 1 May and at retail stations starting on 1 June. EPA is providing relief by extending the 1-psi Reid Vapor Pressure (RVP) waiver that currently applies to E10 gasoline to E15, which will enable E15 sales throughout the summer driving season in these areas, if necessary.

This action only extends the 1-psi waiver to E15 in parts of the country where it already exists for E10. E15 can already be sold year-round in parts of the country that have a Reformulated Gasoline (RFG) program.

Because the RVP of E10 and E15 gasoline used by consumers will be the same (both will be 1 psi higher than otherwise required by EPA or state regulations) EPA does not expect any impact on air quality from this limited action. EPA’s research has shown no significant impact on evaporative emissions when the 1-psi waiver is extended to E15.

With no significant impacts on emissions from cars and trucks, EPA expects consumers can continue to use E15 without concern that its use in the summer will impact air quality.

EPA’s emergency fuel waiver went into effect on 1 May when terminal operators would have otherwise no longer been able to sell E15 in the affected regions of the country and will last through May 20 which is the statutory maximum of 20 days. EPA will continue to monitor the supply with industry and federal partners, and the Agency expects to issue new waivers effectively extending the emergency fuel waiver.