A 10% tip suffices in most restaurants unless the service is exceptional. Porters in hotels and airports expect S/2 per bag. There's no need to tip taxi drivers, although many people round up the fare. At bars, tip about S/1 a drink. Bathroom attendants get 50 céntimos; gas-station attendants get 50 céntimos for extra services such as adding air to your tires. Tour guides should get S/20 and bus drivers S/10 each per day.