(AP) — Several plaintiffs have agreed to dismiss claims against 15 companies in longstanding lawsuits involving allegations that oil companies and gasoline retailers overcharged consumers by selling “hot” fuel that contains less energy.

Federal officials earlier consolidated about 50 lawsuits filed since 2006 from consumers across the country in the U.S. District Court in Kansas City, Kan.

At issue was whether customers are shortchanged when buying gasoline that’s over 60 degrees. The volume of gasoline expands, and consumers argued they got less than a gallon of fuel for a full gallon price.

Plaintiffs’ lawyers agreed last week to dismiss claims in Kansas federal court in 22 cases against 15 defendants, which included 7-Eleven and Circle K stores.

Several larger retailers, including Costco, Wal-Mart and Valero, earlier reached settlements in their cases.