Although Formentera is a small island (only 17 km long) it's worth renting some kind of vehicle to explore it by yourself during your stay on the island.
You can rent bicycles, cars, quads or motorbikes. There are several renting companies, located in La Savina Port, Es Pujols and near hotel and apartment zones. If you choose motorbike as your vehicle, please be aware that roads seem safer than they are!! So take care as every year there are several accidents. Many people prefer bicycles as they are pollution-free and distances are manageable. Formentera has several green routes that are perfect for bicycle lovers.
There are also public buses that cover the island. The circuit bus travels from Far de la Mola to El Pilar, Mirador, and Sant Ferran. From Sant Ferran it loops around Estany Pudent via Es Pujols, Illetes, Port de la Savina and Sant Francesc. The route is divided into a short circuit which covers Port de la Savina, Illetes and Es Pujols, and the long circuit which covers all the stops. Between May and October the bus runs the loop between La Savina, Es Pujols, Sant Ferran and Sant Francesc every half and hour. You can check schedules at all bus stops and also in the tourism offices (La Savina, Sant Francesc and Es Pujols).