This legislation primarily amends the Clean Air Act to address regulations concerning ethanol-blended gasoline and the Renewable Fuel Standard. A key provision extends the Reid Vapor Pressure (RVP) waiver , currently applicable to E10, to gasoline blends containing 10 to 15 percent denatured anhydrous ethanol. This change aims to facilitate the year-round sale of E15 by ensuring it meets RVP requirements during the high ozone season, thereby increasing consumer access to this fuel blend. Furthermore, the bill modifies existing RVP limitations, explicitly changing the applicable range from "10 percent" to "10 to 15 percent" for certain fuel blends. It mandates that states previously subject to the 10 percent RVP limitation will now have the 10-15 percent limitation applied to qualifying ethanol blends upon the bill's enactment. This ensures a consistent regulatory environment for E15 across affected regions. The bill also includes provisions to assist small refineries under the Renewable Fuel Program. It specifies that Renewable Identification Number (RIN) credits retired by certain small refineries for the 2016, 2017, and 2018 compliance years, particularly those with outstanding or denied exemption petitions, shall be returned or applied to their accounts. This measure provides financial and compliance relief to these refineries.