Lexus recommends refueling with unleaded gasoline with an octane rating of 87 or higher. If you use fuel with an octane rating below 87, you might hear engine knocking, which can lead to engine damage.
Once you’re done filling up, screw the gas cap on clockwise until you hear a click. Then, push the fuel door closed, and that’s it! The fuel door locks whenever you lock the car doors. Oh, and if you hear a warning buzzer when you start the car, it means the gas cap is loose. You’ll also see a message on the multi-information display. Just tighten the cap to stop the buzzer.