2007 Toyota Prius Owners Manual - Page 67
2007 Toyota Prius Manual
Page 67 highlights
CAUTION D Make sure the cap is installed securely to prevent fuel spillage in the event of an accident. D Use only a genuine Toyota fuel tank cap for replacement. It is designed to regulate fuel tank pressure. NOTICE To prevent damage to the cap, apply force only in the turning direction to the cap. Do not pull or pry it. 50