Derfish is right. East from SPM there's no petrol station along the new highway until the Punta Cana area, three toll stations but no petrol station. There's a new station after the turnoff to Bayahibe, and the old Isla Gasolina on the old road towards Benerito. There's also a new station in Villa Hermosa for those taking the risk getting lost down there, still easier to get to than through La Romana. It used to be one Isla Gasolina before La Romana along the old road, but that was closed when the highway opened.