The S gear in a Toyota Camry indicates the sport mode. This mode is designed to provide the driver with a more exhilarating driving experience by making the car more responsive to accelerator input and increasing the engine speed. The sport mode can be activated by pressing a button on the center console. When the sport mode is engaged, the car's engine speed will increase and the car will become more responsive to accelerator input. The sport mode is best used when the driver wants to have a more exciting driving experience or when driving conditions warrant a more responsive car.