Puma to Sell Gasoline-Ethanol Mix in Puerto Rico A Swiss oil company says it will start selling regular gasoline mixed with ethanol as part of a pilot program in Puerto Rico. Puma Energy Caribe LLC says 56 gas stations across the island will participate in the program starting Wednesday. Puma says that if the program is successful, it will extend it to all its gas stations in the U.S. territory. Ethanol is routinely mixed with gasoline on the U.S. mainland as part of a 2007 federal renewable fuels law. Puma last year bought all of Chevron's gasoline stations and underground storage tank facilities in Puerto Rico and the U.S. Virgin Islands. The agreement included 185 Texaco-brand gas stations in Puerto Rico and seven stations in the U.S. Virgin Islands.